I know this is a fairly old thread but I thought I'd post my views on steam.
I don't like steam, I feel that it's something I have to put up with if I buy a game off them.
For example, the steam community system pops up the notifications in the bottom right hand corner, and you can't change that. However, this is where many strategy games have their control panels so if you want to play a strategy game on steam you either have to put up with groping around blindly for an order whenever a friends notification pops up or turn of the steam community system. I'm sure they've had numerous complaints about it and they've been selling strategy games for a couple of years now yet it remains unchanged.
Another example is the 'notify me about additions or changes to my games, new releases and upcoming releases option'. For a start, news about games I own and advertising are two entirely seperate catagories, there's no reason they should be combined. Not only that, but the game updates hardly ever seem to get updated and most of the game updates I don't get notified about while you get new adverts popping up several times a week.
It has numerous other issues like the way it installs itself silently to run on startup without asking permission, the version system (or rather lack of), the lack of an option to shut it down when I'm done with it and of course, games that have mysteriously stopped working because the authentication server has gone down and the people trying to run the game haven't been told.
And then the ridiculous price of the games, Empire: Total war in