I'm the opposite, I loathe big laptops. I always used Thinkpad X's or the Vaio Z's connected to monitors. That way when I leave I just pop them off the dock and carry them out the door with my paperwork. Take 'em to a coffee shop or out on the porch and get some work done. On that note, I can't do the 11s though. I initially had an 11" MBA and that was way too small.
Fair enough. Though, my 15" rMBP is slightly lighter and 40% thinner than the 12" PowerBook G4 that used to be the height of portability not too long ago.
I'll never do another 15" laptop!