The other thing with professional reviews -- and I think you mentioned this in that Wonderful 101 post -- is that you're being forced to play games under a time limit and that WILL effect how you respond to them. Also I'd assume that the professionalism means you get less emotionally involved and less prone to, uh, the sort of goofy fan rants that plague the metacritic user reviews?
I think we're less likely to take a game personally. I'm RPG-girl and while I certainly have my preferences, I have played so many different games from different publishers there's no room for irrational hatred. It's the same with shooter-guy. He might prefer Battlefield over Call of Duty but has to play both. He can't be all xenophobic like some of those ranting metacritic users are. Plus, this line of work encourages you to try new things with an open mind all the time. If you can't do that you won't last long. And because we have to play everything that is thrown at us, we'll actually play some of the worst games ever. The stuff normal gamers wouldn't touch with a ten foot pole. If you've been around for a while, you know what true horror looks like. And nope, it doesn't look like the newest Call of Duty. True horror has the face of Superman 64, Astro Boy: The Video Game for DS, that shitty pool game for the Wii I don't want to remember. We survived that, so of course we're not going to give an uninnovative but otherwise fun game a 2.
It's the same with consoles. Back when I wrote for a Nintendo magazine most of my co-freelancers had systems from other companies as well. Plenty of PC-gamers too. Not because of work, but because they loved games.
Not that we can't get enthousiastic about the things that are truly awesome. It's great for us because it makes it easy to play a game for longer periods of time, and it's great for readers because will probably sacrifice our spare time to see as much of the game as possible. For instance, I was asked to preview Hearthstone and got a betacode to do so. That was over a month ago, but I enjoyed the game so much I still play several matches every day. By the time the game is finally released I'll have a good understanding of the card selection, how the game is balanced and so on. I'm looking forward to reviewing it.