What would you do if you owned Spirit. Here's what i'd do.
1. Increase seat pitch to 29 inches, and scrap big front seats. Instead, leave the bulkhead partition out and keep the seat width at 18 inches, reducing aisle width by 1.5 inches.
2. Remove carry-on charges and reduce checked-bag charges to $30 per bag
3. Increase fares to make up for loss of ancillary revenues