Why must you be careful when using "www. tripadvisor .com" to research hotels? It's because a lot of the reviews are totally bogus because ANYONE can post. This includes people who have never used the hotel in question.
Some reviews are overly positive. Often it's the hotel plugging their place using multiple Trip Advisor accounts. Some are negative to the point of slander. Quite frequently it's people who know the hotel owner, perhaps, and have a grudge.
If you want a much more accurate idea as to whether you should stay at a hotel then use the Expedia or Travelocity reviews instead. Those sites only allow you to post a hotel review if you have actually booked the hotel through them and completed your stay.