I have always "tolerated" Steam but another annoying use of it showed its head to me last week. When Steam autoupdated my TF2, it corrupted some files. Apparently when it corrupted these files, it did something to my registry as well.
The game would hang on preparing game files, and, when I managed to get around that by deleting all my Steam files 2x, it still refused to read off the DVD and wanted to dl the entire orange box of games through Steam, and at 20kbps max.
Once I dl'd just TF2, I was able to coax my old files to work again by copy and pasting them, but what a major pain in the ass. I had to wait 30 hrs. for it dl TF2 again, after spending a day and half trying to NOT do just that.
On a sidenote, I couldn't install the single player games either, in offline mode or not, because Steam just HAD to verify and hang at the same point each time. Totally maddening. If I have a choice between a game on disc or any sort of link with Steam, I will take the DVD from now on, hands down. I just hope 3rd party developers don't integrate as tight with Steam as Valve does.