I just bought a Giant TCR C2 at Performance on the 6th of this month, but before I did, I asked about the contract termination w/Giant. My LBS assured me that service through them would not be affected.

I use mine for commuting--10 miles one way. No problem, because I don't find using a backpack a problem as long as the backpack has waist and chest cinches.

My K2 is in the shop for a new drive train, but it'll probably wind up becoming my GF's bike.