Yeah, I def. Would not take a connection on them (or even a nonstop) if I had to be somewhere without possible delay.. or just make a backup reservation on DL, UA, AA or whoever you trust for AFTER the Frontier flight time and cancel the backup one when they close the door and pushback on F9 and you know youre going for sure- thats what I did- just in case.. (You got to do it before you take off, because they have no in-flight wifi.) Short, nonstop flights, if their schedule happens to work (which seems random)..But if those conditions are met, save most of your money instead of giving it to DL and go ahead and fly Frontier...