Ground service is great when it works. I've been quoted ridiculously high rates or long waits because there was no back haul or my dog was the only one getting a ride.
I've used the airlines for years without any problem. Continental was great but they were bought out by United and I haven't been disappointed. Just picked up a new chessie pup last week that flew United.
Air isn't really an option for me. The breeder and I both live a long way from major airports so door to door ground service is way more convient and cost effective.