CP -

It all depends on the fare class you fly in the most. I'd recommend DL if you don't fly on the lowest fares - you can't upgrade on those "L-class" fares. Plus, as mentioned, the system-wide upgrades are great.

CO, however, has a better upgrade policy on lower fares. And, better overall service. I just got comped on CO in 10 minutes on the phone - just sign up for RewardOne on their website and then call the RewardOone line and ask for an immediate comp.

But, overall I'd go with DL because their schedules out of TPA via ATL are most convenient.

Carberry