I'm a self - confessed, serial reader of reviews. Trip Advisor, Booking.com, Hotels.com. local area forums on the internet etc. I wade through pretty much all of them when planning to go somewhere new for a week or two.
I'm the same with buying stuff - "Which" magazine and their online reviews are an essential part of my buying process.
As Mercury said, it's the bad reviews that remain with me. I'll then check the poster's other reviews to try to determine their "neutrality".
Suggested room choices in a particular hotel are always interesting as are the features about things to do in the area.
Restaurant reviews, whether here or abroad, are an absolute must. If enough people give top marks and write informatively about good food quality and high service standards, I will go out of my way to try that place.
Having retired, I try to get away a few times each year and every trip is planned as best as I can to minimise disappointment
I scrimp and save to have the best time I can afford and the "research" is, for me, a wholly enjoyable part.
There's always going to be a few exploratory days to wander off and take a chance with somewhere new.
With Trip Advisor particularly, I check the reviewer as much as the review.