Executive Airshare is Very volatile
I worked for Executive Airshare in 2005-2006 and can vouch for the demand it puts on their pilots. While I was there their policy went from 3 hard days off a month to 1, mainly because they were tired of paying bonus pay on the pilot's hard days off!
While the pilots were great to fly with, they were looking actively for "greener pastures". Proline 21 is a pipe dream, as stated earlier. This is definitely NOT the family-friendly corporate job!