Vainamoinen: I don't know how I'd feel about removing existing non customer reviews. I'd be for preserving those as legacy reviews, but not accept new ones.
Sure, but I feel the system isn't that bad to begin with. We get stupid reviews at times, but how common are they on average? If most of the "non-reviews" reviews are from people who don't own the game on GOG, I can't say, but that's probably something GOG would know better than me, so I concede it might not be worthwhile to keep the feature, I just didn't have a bad experience with it personally, overall.
Vainamoinen: Life's a popularity contest anyway, why measure a review's popularity at all? I think it would be an interesting idea to implement a random sorting mechanism.
I am not sure that's a good idea, but if it was available for those who want it alongside the "regular" system, I wouldn't mind, of course. While some reviews might abuse the system, the overwhelming majority of the ones who raise to the top are the more articulate reviews (among the early ones), and those are still the best in the short term to get a feeling for the game before a purchase. They aren't necessarily the most accurate ones, mind you, but not many people might go back to the reviews after they play the game for themselves, just to rate who was wrong (unless they feel strongly about the game).
Vainamoinen: "Getting into the green" is yet another silly popularity contest that people are attempting to "win". If you see at first glance who upvoted a post, you can assess if an opinion indeed is popular or if the author is so insecure about himself that he needed to make his post look like it is more popular than it actually is.
I mean, sure, but is that really important? I know which posts I agree/disagree with regardless, and I can't imagine anyone can claim much just for having an undisclosed amount of upvotes. Once again, it's not like I am against the feature, but it also doesn't seem vital. I guess if the forums ever got a significant update, this feature would likely come bundled with it, though.