I know it's been several months since this thread's had any replies, but I just want to say, ditto on all this. I just took my first Frontier r/t flight -BWI to LAS. I have no complaints about their policies or my experience, but I came to the same conclusion about only considering Frontier for short flights. The nonstop flight to Vegas was 4.5 hours and a total grind. I'm only 5'1 and average built, but I felt pretty uncomfortable and cramped.