Also, we get zero priority on Republic flights, even under American Eagle. You can be beaten out by a Delta guy on a YX American Eagle flight if they check in first. Just make sure you understand the implications of that. Commuting on mainline flights is a completely different ballgame than regional carriers. Your flight cancels due to weather and the next flight is mainline? List for that jumpseat (if not taken by an AA pilot(s)), and it's yours. Your flight cancels and the next one is YX American Eagle to JFK? Sorry, the Delta or jetBlue guy already got it.

I respectfully disagree with those who imply there isn't a big difference. Yes, you're covered by the commuter clause either way, but you don't want to push it on probation with too many misses, deal with the stress, or lose out on the money of missing out on trips.