I use it to help pick a place from my shortlist of, typically, 3-4 hotels per destination that I identify based on price/star rating/location.

I never put much weight on individual reviews... it's more the broad strokes that I take note of. I also find the photos people take to be quite useful just to see what the place looks like in real life. (Although I have written close to 100 hotel reviews, I confess I've never posted so much as one photo mainly due to the PITA factor)