Our 1st and only flight on Spirit was out of LBE last June to MYR.
We had near 9 hour multiple plane equipment issues on the plane that was leaving from NY, another stop, to LBE, then MYR.
Customer service in terminal was horrible, found out they had 'gifted' the one waiting area with food vouchers for snack shop located on cleared side of TSA, the other half (me lol) got squat. Wouldn't be so bad except other than a white tablecloth restaurant all they had were 2 vending machines which ran out mid afternoon.

Couldn't leave to grab food or drink as people were afraid the plane would arrive in our absence. The desk/manager on duty insisted they weren't allowed to inform the 2 different flights' passengers (yes, the flight scheduled to FLL had the same equipment issues is that a coincidence or what

)when the replacement planes were in the air.

They did keep moving back the expected arrival time every hour or so though.
We finally got cleared for our flight, and the FLL one was cancelled as soon as we cleared security.

Felt so bad for them, many were to be cruising the next day and no flights were scheduled for another two days out of the airport.
I wrote a certified letter to the CEO of Spirit, never received a reply, although they did accept it. I sent a second one with the same results. I did manage to contact via phone a regional manager who indicated that they clearly state they only refund the price of the ticket and rarely can you find a a seat on the next flight out during busy season. Every other airline on which i've experienced a long equipment issue has offered goodwill/vouchers, etc.
Things happen, equipment issues naturally must be addressed, etc. but our experience was just one thing after another. IMO this airline's business model leaves much to be desired. I'm a gambling woman and realize the odds of this perfect storm of a crappy travel experience happening again is unlikely, still I won't take a chance no matter how low future fares may be out of LBE.