From one quick look at f.e. GameSpots reviews and its users, I cannot trust the users as their "reviews" are 5 sentences long.
A review must mention pros'n'cons and tell you what works and what doesn't.
About professional reviews....I'm looking for a gamereviewersite to become my "home" for gamereviews but it's hard to decide. PCGamer is out of the question because of their "75% from us means 50% from other magazines" <--- Yes they've said that! They're inflating scores and affecting metacritic!
Another thing which I believe is that reviewers MUST mention what types of games they like and what they don't like. In SuperPlay many years ago the reviewers were listed with their preferred gametypes and what they didn't like.
In one number, they reviewed DOOM for Playstation (this was back in 1995.) One of the reviewers, a guy called Martin-san (san is a honorary title used in ancient Japan. He loves JRPGs like Final Fantasy and such) reviewed it and part of the review went like this: "Zzzzzz.....shoot monsters, get blue skullkey, enter blue door, fight more monsters, collect weapons and ammo, get in trap and fight Barons of Hell and Cacodemons very close to you. Die 3 times until you survive. I really hate games like DOOM."
He gave it 42%(!)
The other guy who reviewed DOOM likes shooters and gave it a high score. Don't recall the score but it was what a FPS fan at the time would have given DOOM. Like atleast 85%.
I wished there were more reviews like that since it shows a a review from two different perspectives. One that loves the genre and another guy who dislikes it.
Kinda like if I had to review Baldurs Gate or IceWind Dale. Without help I wouldn't have gotten anywhere and would probably give it like 50% or something.