Sounds like you pretty well thought it through, and I would say I would jump too.

Actually, I’ve been in a very similar situation and did jump…worked out fine.

The only things I didn’t hear you mention:
– how does going back to being the newbie sit with you. With any new job, there is a steep learning curve even if it is in a field you know well. My head hurts for months after taking a new position…I go home with my head swimming with new information…maybe I should buy a heat sink and CPU fan for my head when I start something new.
– this goes hand-in-hand with having to start at ground zero building up your reputation again. At my current employer, my reputation is so solidified that I can pretty much pick the plum assignments as they come up. If I jump ship again, those years of building that reputation gets thrown away and I will have to scrap with everyone else for the plum assignments. This is a strong incentive for me to stay put at this point.

Those things are somewhat offset by the fun of learning something new, meeting new people, getting a new desk, driving new roads, etc. Ruts get boring.

Since you are far enough along in your career that your family won’t starve should the new position not work out, I think you can safely jump if that is what will make you happiest. From your post, that sounds to be the case.