I can't say I've had any problems with Yelp on the above level but I rarely use one source to decide where I'll spend my money.
For restaurants I tend to use reviews written by professional critics found in newspapers, local high production magazines, Zagat's, and travel magazines. Much the same resources for hotels although since I worked in the industry I've a pretty good idea what chains I prefer to stay in.
For me sites like Yelp and TripAdvisor are for a different on the ground review and I read them after going thru my first sources. Maybe they'll tell me something about what side of the hotel has more sunlight,post personal pictures, etc.
I accept that when posting on individual based review sites some people have an axe to grind and others are less than articulate. Good example: "We had a great time and will go again!!!!". I read those reviews as various forms of fluff and rarely retain them in my brain.
Angie's List is a site I've never been interested in paying for the privilege to use.
