I only care for the agregate rating.

If a game has a 4* rating on GOG, I know it has serious problems. If a game has worse than a 4* rating on GOG, I know it is crap.

Can't say I do. I am already somewhat familiar with most GOG games (even before I bought them), so I don't really need yet another opinion on them.

And anyways, if I want opinions on older games, I usually head to Mobygames user reviews.

I read GOG reviews and take them into consideration but then make up my own mind. I don't just look at the stars. Once you read them you can tell if the reviewer is nostalgic or if his taste is similar to yours or see why he liked the game so much. I usually ignore the "buy this game! highly recommended!" review types. Sometimes, a feature a reviewer considers important or fun is neither of those things for you and vice versa, so I really read them through and judge for myself if the game's worth it.

Also, GOG reviews are never the only factor I use to decide if I should buy a game or not.

Not really. Might read a couple of different ones that give vastly different scores but in the end I don't take them into account.
But I don't read reviews on games anyway. Not here, not anywhere. Same shit, different asshole.

I only watch Youtube gameplay videos to decide whether I'll like a game or not.

They're reviews the same way Kotaku is a bastion of games journalism. It's pathetic. The reviews are always biased or it's been C+P'd from some Amazon review or somewhere else.

Wow,I wonder into anti-review troll's den.