I the same "problem", only bigger (more games installed), but it doesn't worry me at all. Much better than downloading the patch umpteen different times on my slow internet when I can just store it on a cheap HDD, or steam deciding that, "sorry you can't play now because I want to pull 50gb worth of patches in RIGHT NOW".
Well, i back up my Steam games to my back-up HDD, so installing a typical (patched) Steam games only takes a few minutes.
When my Steam games are finally fully installed, i take it OFFLINE.
- i never really have to go online again with Steam