One thing that you might want to do when choosing a web host is to hunt around looking for what sorts of things that people have to say about the particular host. If the host is particularly bad for any reason then typically you will be able to find plenty of comments around that tell you that.
You can't just take all the comments that you see at face value though or you will end up deciding that all web hosting is bad and that you need to look for an alternative to using a hosting provider to host your site. What you need to work out is how to read all the comments and to understand what they are all saying so as to determine which hosting providers are truly bad and which just have the expected few people for whom the hosting didn't work out.
There are a couple of different things we need to consider when examining all the bad comments that we see about a particular web hosting (we'll concentrate on the bad comments because most of the satisfied users have better things to do with their time than to write good comments so most of the comments you find about any web host will have been written by someone who had problems and decided to tell others about it).
Firstly, the actual number of bad comments by itself doesn't mean much. You have to also consider the size of the web hosting provider. A hosting provider that hosts 1,000 sites and has 100 bad comments about them has far fewer satisfied customers than a hosting provider that hosts 1,000,000 sites and had 500 bad comments about them. Unless you can find out the actual number of sites that a provider is hosting you can't judge how good or bad they are from the number of bad comments. In fact that a hosting provider is hosting 1,000,000 sites is itself an indicator that they mustn't be too bad since if they were then why do so many people host with them. That doesn't mean that a provider hosting only 1,000 sites is necessarily bad though since there can be many reasons why they want to keep things small and with just a small number of hosted sites the service may be far more personalised.
The second thing you need to consider is what the bad comments are actually complaining about. The complaints can be broken up into two groups - those that are the hosting providers fault and those that are the site owners fault but where the site owner incorrectly blames the hosting provider. Unless you can recognise the difference between these two groups of bad comments then you will not know how much weight to give to each. In the case of the second of these groups what you need to understand is that no web hosting is perfect for every possible site and this second group of bad comments is a sample of sites where the hosting wasn't suitable. This is where an understanding of the requirements of your site compared to what the particular hosting offers will help you in determining whether any of this type of bad comment may also be applicable to your site.
So what we need to do is to closely examine what the bad comments are actually saying so as to determine whether they are actually saying that the hosting provider is bad or just saying that the hosting isn't set up to handle a particular type of site.
If the bad comment is about the site always going down for exceeding resources then there are two possible causes - either the site is running inefficient scripts that use more resources than needed or the site requirements are greater than that offered by the hosting. In neither of these cases is it the hosting providers fault. The site owner could have fixed inefficient scripts to get them to run within the resource limits or alternatively could resolve their problem by moving to hosting that provides the resources they require. This sort of bad comment is only relevant if your site is using a similar script and has similar visitor numbers to the site which the comment is about.
If the bad comments are about how long it takes for the server to come back up after a crash then the problem is that the hosting provider is allowing too many files to be loaded onto individual servers. If you see this type of comment then you need to look around to try to find out what actin the provider may have taken since the comment so as to limit the number of files that there might be on each server.
If the bad comments are about the limits that the hosting provider has then you need to compare those limits with what your requirements are. If your site comes nowhere near the limits then bad comments from sites that exceed those limits don't mean anything to you.
If te bad comments are about the hosting support not providing help in fixing problems with the scripts that the site is using then you can probably just ignore them. The hosting providers are in the business of providing the hosting and leave it to the site owners as to what they use on that hosting. You can't expect a hosting provider to support any script that might be installed on their hosting, the script authors are the ones who should be providing that support. Now if the comment is regarding how the hosting doesn't provide everything necessary to be able to run the script then that may be something to note if that script is one you intend to run. Of course the commenter may just have not asked the right questions or made the right request and the hosting may actually support the script if you make the right request to support to get the hosting configured appropriately. It would probably be easier to just look for a different hosting though unless you strike the problem with your current host and would prefer not to move.
Generally when examining the bad comments you need to ask yourself questions such as - what sort of site is this comment referring to? Is the comment about something that relates to the hosting or is it something more specific to that site? Is the fact that the hosting support failed to resolve the problem an issue with the support or was it a failure on the part of the site owner to properly clarify what the problem was that they needed fixing? In a lot of cases the problems are mainly of the site owner's own making. Of course if they do not have sufficient knowledge to be able to properly identify what is happening so as to correctly explain their problem in order to get help that isn't really their fault either since most people building web sites do not have the technical expertise to be able to work out how to properly word their questions. That can mean that many of the bad comments about a hosting are due to someone having had issues trying to get their site to work there without being able to give anyone enough info to get the help that they need.
That doesn't mean that all of the problems that result in bad comments are the site owners fault. In some cases it is the hosting providers fault. They may be placing too many sites on each server. Their support staff ma be useless or uncontactable. The server may actually spend more time down than up due to issues that they can't be bothered fixing.
The difficulty is in recognising the circumstances relating to each of the bad comments that you see about a given hosting provider in being able to determine which are applicable to your circumstances and which are not. A lot of it is also going to be luck since even the best hosting provider will have server problems at times. If they just happen to have massive problems with one of their hundreds or thousands of servers just after someone moves their hosting to that provider and is placed on that server then what sort of opinion is that site owner likely to have of that otherwise good hosting provider.
You have to weigh up all of the comments for what they say and what you can determine of the circumstances. You need to try to find out how many sites that the provider is hosting and consider the volume of bad comments in comparison to the number of sites. Not all of the information to do this will necessarily be available and you will have to make a decision based on what you do know.
Since you may find after all this that you still ended up choosing hosting that may not be right for your site the one other thing you need to look for at the start is what sort of situation will you be in if you need to leave the hosting soon after getting it. Some hosting allows you to pay monthly so you could just pay for one month to start with so as to limit your out of pocket if you chose wrongly. Some offer a pro rata refund if you leave before the end of the period you pay for so that you can get most of your money back if it doesn't work out (if people have issues getting their money back in this sort of situation then you'd find bad comments about that). Some providers will even refund all of your money if you discover that their hosting is unsuitable for your site within a specified period of purchasing the hosting and will refund all your money.
The important thing is to properly research things when choosing hosting in the first place so as to maximise your chances of selecting suitable hosting and minimising the possibility of problems.