For others who ask questions like “how is the flying out of XYZ base?”:
We are a point to point airline, not a hub and spoke model. Most multi-day trips it is unlikely you will pass through your domicile until you return on the last day, but it is not uncommon to fly into or layover in other domiciles. For this reason there is not really a lot of proprietary flying in one particular base that makes it wholly different from another. Because it is the most western base, there are more red eye flights that originate out of LAS, but that doesn’t preclude you from flying those same red eye flights on a trip that starts from another base, the same way that the red eye night turns out of FLL are not exclusive to pilots there. Seniority and location of domiciles are much larger factors than perceived trip quality.

As to your question about QOL, many parts of that are subjective and anecdotal. A line item contract comparison (excluding compensation) is difficult to compare without seeing the results in action. Apples to apples schedule quality and flexibility at Spirit tends to exceed legacy narrow body counterparts, which is an often something that those who have flown at both types of companies concede on these forums.

Attrition tells only part of the story while in the middle of an unprecedented hiring climate. Obviously those on the upper third of the seniority list have less to be gained from going to another carrier when taking into account their current schedules, the financial hit of starting over, and less time to recover seniority in their career span. Those in the bottom third tend to have more to gain based on those same considerations. The more interesting question would be those in that middle third, who would be more qualified legacy applicants based on 121 and narrow body experience. Do some of them leave, sure, but of those I’ve spoken with the reasons trend more towards either basing or widebody opportunities vs. lifestyle unhappiness. The other intangible for some is that we aren’t a fancy company and the nature of the operation and its clientele carries a stigma both with the general public and other pilot groups. Some pilots aren’t able to see past this and despite their contentment with work rules, and feel the need to seek employment with a carrier that more aligns with their perception of this career, and so be it.

TL/DR: If you need a bullet point argument for why Spirit pilots are happy with their QOL, a legacy pilot could easily list a number of counterpoints why they are. What matters more is if you can see yourself happy flying in our type of operation.