I'd say TA is as reliable as any compilation of random strangers' opinions is likely to be. I use it frequently but not to be taken as gospel truth, just as one resource to aid in researching and deciding.

Reviews with plenty of pictures are ideal, and really the photos are one of the big things that I find helpful. That way I can see the rooms and property in something other than hotel-produced marketing photos...this alone has made it worthwhile for me on several occasions.

It's hard to know to what extent the reviewer's expectations and perspective really match up with your own, though sometimes you can pick that up from how they word the writeup. I do try and look for any major trends in reviews - e.g., lots of people over time complain about poor housekeeping service.

Sometimes info about nearby transit, attractions, neighborhood quality, and such, can be more useful than the property review itself. A big turnoff for me is seeing the Management arguing in an emotional and unprofessional way with their response to a negative review.

I wish something could be done about the obvious fake reviews, realizing you'll never 100% clean that up.

And then you have the "helpful" abuse...like with CMK10's example, maybe the system shouldn't allow more than X number of votes within a certain time period.