So, for the record, my own experience with Allegiant was pretty terrible. Check-in worked fine, though; I checked in about 23.5 hours out on both legs and was given a window seat on the front half of the plane. So that part was good.

My outbound flight was delayed 21 hours due to a cascade of issues; mechanical with the plane, some weather, crew time out, second mechanical with the plane, second crew time out, and finally a 95-year-old passenger who was checked in as having boarded but had managed instead to wander off somewhere in the airport, necessitating that security track her down. (Okay, the last wasn't Allegiant's fault, probably.)

I asked the mechanic who'd been working on the plane, who happened to be sitting behind me when we finally took off, what the second mechanical had been. He rolled his eyes and said "co-pilot user error." That didn't exactly fill me with confidence, although the fact that the mechanic was willing to be on the plane was at least a little reassuring.

My conclusion based on this and a general look into Allegiant's cancellations and on-time performance in the last month or so is that they've expanded their network drastically beyond their capacity.

Oh, and total compensation that we received: $50 voucher toward a future flight, plus free snacks and soft drinks for the maybe 20% of passengers who stuck it out the full 21 hours. The gate agent promised us $100 vouchers. I'm torn between calling and complaining about the difference, or just letting it go on the grounds that even for free I probably wouldn't fly Allegiant again. Around hour 18 we were told that if we bailed on the flight, we could receive a refund; before that, the gate agent told us we could only receive our money back in the form of a credit for a future Allegiant flight, because it was just a delay.