I left a regional in 2007 to work at FlightSafety (one word folks). Became an instructor, check airman and eventually a Manager. My decision to leave the regionals was for QOL, home every night and decent pay. I received job offers all the time, but never jumped due to my satisfaction with FSI. 5 years later, as the kids got a little older, an opportunity came up flying a large cabin aircraft for an operator based in the geographic area both my wife and I were from. The pay was good and the pilots/management were great guys, knowing them firsthand from training at FSI. I took the leap after 5 years at FSI.
I worked at 2 different FlightSafety Centers over the past 10 years, and I can say that the company is steadily evolving away from Al Ueltschis vision. It has become more of a money making, don't give a crap about the employee type operation. Pay raises are minimal, expect 2-4% per year and the ability to move up the corporate ladder is near impossible. The center I worked at had great Center Management, but other Centers I went to, not so much. It depends on where you go.
Good luck to anyone taking the leap to FSI, it certainly can be a shoe that fits for some, for others, not so much.