It always depends on the individual and his particular situation, but the biggest factors are probably:
- What are giving up to make the move? A ten year regional CA with a 6-figure income and good QOL has more to lose by making a move than a junior regional CA or FO.
- What do you expect to gain from the move? Key factors are your age, the compensation package of the new employer, and the age of the pilot group (which translates into your upward mobility).
- Family disruption. A single person can always afford the paycut and move wherever, a family might preclude this.
- Regional Stability. A regional can lose its contracts and/or move domiciles with about 30 days notice...and being 55 years old with 30 years seniority won't help you one bit. Majors are less likely to experience such disruptions, and you will see it coming in advance in most cases.
IMHO, most regional FO's and junior CA's (less than 8 years or so) have no excuse not to make the move unless they are unqualified (degree, DUI, etc) or are too old (40-50+ IM0).
There are exceptions...a lot of LDS folks at SKW for example start large families early and want max QOL without disruptions, so they plan on staying put. Ultimately it is up to you...