Orange Sky is on it. Spirit is great if you know the drill. Newest fleet of planes. Nothing like Frontier or god forbid Allegiant.
If the fare is cheap enough then check and buy the bag when you book. It costs more at the airport to do this. Nothing free on board. Snacks and water cost extra just like booze. I’ve flown them close to 10 times and it has been smooth sailing.
One more thing. Make sure you check in online beforehand. If you need to be in line for the counter/person for some reason to get your boarding pass you will be charged a small fee.
I have taken an extra carryon a couple of times without incident. If you have a topcoat on for instance I have hidden a large laptop/satchel under my coat while visibly carrying on my other small carryon at the gate.