The stuff only really works when you've got something resembling broadband- and ISDN/IDSL doesn't count... Dialup breaks a lot of things upon the wheel because most developers when they do network-centric stuff don't take into account evil latencies and other similar problems when you talk dialup or slow always-on connections.
- another time I wanted to start HL2 after more than a year I didn't played it Steam gave me a weird error that prevented the game to update. And if you don't update you can't play. I had to search the forums, delete some configuration files, reboot, dance, swim, pray, start steam, update, start half life, wait 3 minutes and then I can finally play.
So I personally rate Steam as one of the best crapware™ ever shipped by a software house (just after Windows ME and before the Norton Antivirus "make my Athlon XP behave like a 386" version).