Spirit is okay.
They are a ULCC which is an ultra low cost carrier, meaning the main benefit of flying them is the low price. Generally they will charge you for extra bags, large bags, etc.. They fly the youngest airbus fleet in the world which is nice. There is no first class but there is 8 seats at the front of the plane which are more comfy and have more leg room but I don't think its worth it.

There planes are A319's and carry about 160 people.

There are no free snacks or beverages though they do
offer stuff for sale on board.

I've flown them all over the longest flight being from Fort Lauderdale to Peru and it wasn't bad, the seats have an adjustable head rest but there is not a lot of recline in there seats, but they are faux leather and I guess its nice...

The flight attendants are okay, nothing great on the service, but they get you to where you need to go fast and cheap.