Steam can be a wonderful tool when it works but a massive pain in the ass when it doesn't, problem is it doesn't work or works stuffty 90% of the time.
I spent 4 DAYS installing mw2. When I start it up it doesn't work, I looked it up bla bla bal it said install from disk it should work now. So I try installing from the disk, but steam suddenly takes over and spends 3 hours "installing system components" and then does the exact same thing, spend 2 days downloading and it still doesn't work.
They are so damn cheap that they will take away hundreds of dollars because they almost lost a cent.