My son and I flew Spirit last year, and were unimpressed. For a bargain airline, the tickets were somewhat pricy, and they charged for everything. Most airlines serve drinks and snacks for free, but not Spirit.
Delta, on the other hand, not only served free drinks twice on a 3 hour flight but also several snacks. In addition, they upgraded my seat (free of charge) to one where I had tons of legroom and actually had to stretch to reach my carry-on stowed under the seat ahead of me.
I’ll avoid Spirit in the future.
I’ve never flew Delta, and I never flew Spirit and by your description I wouldn’t fly Spirit either. The worst experience I had though was in March of 1975 when I flew from Chicago to Germany with Lufthansa. You would not believe how unfriendly the flight attendant were. I swore I would never fly with that airline.