I left one of the fractionals voluntarily 6 years ago (flying a Challenger 604). The FSI position represented a 40% increase in pay. Fortunately the center was based in my fractional base so no physical move required. Of course, I'm a glutton for punishment in the sense that I spent 4,000 hours as a primary flight instructor back in the 90's- yes, you read that right. I also have a background in behavioral psychology and did a stint as a middle school teacher so the job fits.

Pay increases at a rate on average 2.5-5% per year. I'll be 42 in May and absolutely miss flying (freight and regional background as well) but it's a trade-off. Have been treated well at FSI and great people and clients. Great tuition assistance (75%) so you can finish a Masters/Ph.D at the same time - and that's been working well. I have received inquiries from clients about coming on with their department but when it got to the final interview the shootdown was - recency of actual operating experience. Who knows if that was accurate, but's that what a follow up call to those that recommended me revealed.