I'm normally on an 8/6, but did a 15/13 one time when a crew member on the opposite rotation needed a particular weekend off. It was not something I (or the wife) would want to do on a regular basis. Some folks take advantage of it in various ways (like far flung vacations during their two weeks off), so it depends on your individual circumstances.
Also, anyone applying to XOJET now should ask a LOT of questions of the recruiting staff. I hear the pay, schedule options, and vacation accrual may not match what current XOJET pilots get...or what is posted on the APC Airline Profile.