I've flown Allegiant and Frontier and the good news is that ticket prices are almost certainly going to go down as a result of this. If you've never been on Frontier before, though, brace yourself. While the planes are "newish", which helps a lot over those decrepit MD80's that Allegiant flies, the seats on Frontier are legendary uncomfortable for anything but the shortest of flights. One thing you will immediately notice is the "half trays" -- literally seat back trays that have been cut to half of their regular size so that the seats can be put even closer together. The seat cushioning is also compacted/non-existent for the same reason. The upgrade package to the exit row seats is definitely worth the cost. Overall, though, definitely worth the comfort sacrifice if the destination is Vegas.