I worked for about eight years for a Fortune 500 (actually its ranking was two digits... and it wasn't #99). Benefits were great, pay was very good since they let me relocate from NYC (cripplingly high taxes) to FL (no state or city taxes) and keep my NYC salary and bonus. Flipside, I'd already had to change career paths entirely within the organization (from engineering to product management) in order to get a promotion, because the peristalsis was just too slow. And on every side, beset by "you can't get there from here" processes and conflicting goals. The analogy I used was that the company was trying to use a standard process built around the nuclear weapons industry in order to make toy dolls, and wondering why it could never get a project finished in time to be relevant. The only turnover to speak of was people who came in, tried to get things done, and were either torpedoed by vested interests, or gave up the struggle and moved on to other pastures where they could satisfy their thirst for meaningful achievement.
About a year ago, I happened across a job posting for a small software company close to my new home in FL. Much smaller, but *DOING THINGS* and generally accelerating upwards. I negotiated the same salary, but no bonus, no 401k match, and generally smaller benefits all round. So I took a "pay" cut of perhaps $20-25k, all things considered, but I do not regret the move for one microsecond; I've already had one promotion, of a sort, and I enjoy what I do (when I'm not cursing at it - hey, this is software, after all! :)). Other people in my position might have felt differently - especially those closer to retirement and looking to stick with a dead-end railroad job to harvest benefits. I'm not young, but I'm also not anywhere near an age where retirement will be possible. And a considerable amount of my personal happiness is tied up in the question "what useful thing did I get done today?"
TL;DR: this is a personal decision and you have to decide how much risk you're willing to stomach. And yes there is the possibility you'll be screwed, either maliciously or simply because your employer had expectations beyond what any one person can achieve. All of us on the other side of the internets can't make the judgement call for you as to whether this is a possible malice situation - you've spoken to this new employer, we haven't - and as for the expectations-too-high part, the way to manage this is with explicit goals, preferably chopped up into slices no bigger than three months. Check in frequently to make sure management knows how you're progressing and what things are slowing you down.