I find that reviews let me see what other people find great about their service, but the ratings also let me see on a scale how different hosts rank against each other from other people who have used their service.
Of course, not all hosting is just your typical basic host for plain HTML pages, so it's nice to be able to compare hosts grouped into categories like ecommerce, linux or windows, control panels, cheap hosting etc.
That helps a lot when you compare three or four hosts with similar offerings, I mean one host is pretty much like another when you compare disk space, bandwidth, or number of domains you can use, but service, that's a totally different thing.
