I think vonerotate and TransMach posts show its up to the individual and the operation they work for.
You express concern about the stability in corporate aviation, yet also the future of the working environment in 121, both unknowns.
You want 121 to corporate captains to respond, but if you'll take the opinion of a corporate to 121 FO here it is.
Yes a type in a large cabin corporate aircraft is marketable if something was to happen to the flight department. Most corporate departments are wary of 121 guys because the expense of traning in can be high, my guess is 30 to 50k for the initial type on that AC. So if you already have the training, future moves in type are easier. From what I've been told by 121 guys commuting, it sux, and there is nothing like driving to your flying job. Less stress equals longer life. Other corporate perks are building hotel, car and airline points that you can really use.
I can understand your hesitation leaving 121 for corporate, afterall if you don't like it, you cant just get back in line where you were.
Good luck.