Don't like the concept of having to find a place to top off my tank every time it runs low ($15+) specifically in remote areas. I would hate to run out of co2 and not be able to air up or engage my lockers... co2 also seems like a waste to inflate a raft, air horns, air bags, its also a little more complicated to hook up everything, as the pressure in a co2 tank is much higher. I have also heard that co2 is bad for air lockers and seals but I have nothing to back that up...
Also got a decent deal on the pump, and air unlimited is free (hopefully)!
Just remembered this thread:
http://www.expeditionportal.com/forum/threads/110607-CO2-vs-Portable-Air-Compressor
"Only problem is the cost of refills and finding somewhere to fill it at a reasonable price. "
Just sounds like another PITA and something I don't want to think about before leaving on a trip... But to each their own.