Well, I just got back from an award trip on them to CTG (connection in FLL). FLL flight was 90 or so minutes and CTG flight was 150 or so minutes.

Both were in the "custom" A320s. They could stand to give another inch of seat pitch, but to be fair it's possible to get the same on some legacies AND an IFE box, which is something Spirit doesn't have. The seats also DON'T recline on the A320s built for Spirit. Flight attendants tend to battle the pax most over electronics and using the lavs when the seat-belt sign is on, plus the front lavs.

As ULCCs go, Spirit does at least as well as Air Asia on the seating config, but of course the bag policy is a real irritant. It IS possible to do a 5-dayer with just a rucksack, though it helps if it's to a warmer climate with fewer clothes needs. CTG was definitely warm.

There's also the "big front seat" as a paid option, though planes don't have many of them.

It works best with short hauls; the longest flight I've had on 'em was DEN-FLL, and the FLL-LIM is likely a DVT causer. On my CTG trip I had two flights at 100% and two with an empty middle seat.

They definitely over-promote the award availability for the reduced amounts (it can be low and you definitely have to book way ahead). OTOH, so far I've booked and done CTG, CUN, SJO (twice), DEN and FLL (several FLL) on awards, so it's had some value.