i had problems with Steam on vista, and it drove me nuts... i think you'll probably find a thread by me from a couple of years ago with the same sort of sentiment towards steam.
But since i got steam working its been a dream, i mean if it works its great it is a great tool, you don't have to hunt down patches on filefront or anywhere else and then wonder what version you have installed and why the patch wont work etc...etc..
I even installed Tales of Valour yesterday, i already have CoH and Opposing Fronts which i bought the retail versions, i thought steam wouldn't be able to understand that i had two non-steam versions and a steam version.... but amazingly when i start Tales of Valour i can also play CoH or OF.
i used to hate steam when it didn't work, but now when i log on and they offer me the opportunity to play through all the half-life games for cheap or Mass Effect for £6, and they include all patches and fixes? i cant knock it.
It took me a while to get over the loss of actually having the box of the game, because i like collecting stuff... but when you are constantly changing your system and re-installing games regularly, shifting through all those DVDs and then having to type ion each CD key is a big pain in the butt, again Steam takes care of all of this.
so i understand your frustration if it has conflicts on your system, but in general Steam is pure amazingness.