I went from corporate/135 to a national carrier, and just recently took a job at a legacy.

I loved my corporate gig - the flying is definitely more varied and interesting than what I did at my national job, and I presume that'll be the case for my legacy job as well. I got to see and do things while flying Citations that I'll simply never get to do again, at any level of 121. I also didn't mind the additional stuff a corporate guy typically has to do - I took pride in it, and there's a lot of satisfaction in a job well done. That's not to say that the satisfaction isn't there in an airliner, but it tends to be more elevated on the corporate side simply because you have a larger role in the overall experience for the passengers.

I left because I was at one of those places that had one crew per airframe, and although I was treated well and not overworked by any means (I flew 12-15 days per month, almost all day trips) - being tied to the phone got old after awhile. I found that as I got older (and married, especially), being at home on my own terms became increasingly important over partying it up in Costa Rica, attending Super Bowls, and so on.

The right corporate gig would have kept me around, and they're certainly out there. But for every one of those jobs, there are dozens of middle of the road ones, tons of downright crappy ones, and after awhile I cashed in my chips and joined the (non-regional*) airline rank and file.

*I can't think of a situation that would have made me head over to the regionals, other than unemployment.