We have also flown Spirit many times, up until this last trip no real problems.
However we flew Jan4 th from DTW to MCO and had an hour delay (waiting for a crew member to show up.)
The flight home we had an almost 5 hour delay on Jan 11th. The plane was supost to leave at 6:30, we didn't take off until 11:15 a night. That was a long and unpleasent wait in the airport. The staff was very poor about taking complaints. Infact since being home I have emailed them and haven't even heard a word back from them. IMO 10% off is nothing. (they didn't actually give it to us, just offered it.) They didn't even offer any food (over a dinner hour and a very long delay.)
If you had asked me earlier I would of said YES FLY SPIRIT, we love them.
Not so much anymore, and after what antmaril said it really makes me think this is more common. Ours was not a weather delay.
DH wonders if their new flights out of the country is making it more compliacted.