I agree with most of what WelcometoBen said above, however, living in base will always be more profitable for the pilot. Being able to go to work overtime on short notice will as well. That is true at Spirit as well as at Delta, United, etc. As a junior captain, I probably get called on 75% of my days off to work extra. I typically don't, but money is there for the taking.
All that being said, yes: pay rates and retirement contribution need to come up. And that is irrespective of work rule changes. Change those at all to our detriment and the price increases dramatically. I have no doubt that 90% of the group will be satisfied with our next agreement.