Personally, I wouldn't move for less than at least 10-15%, and I am a high earner (yes, yes, I am one of the apparently non-existent MN six-figures types), so on paper, the figures look good for you, OP, but as PPs have said, what are the other considerations?
Location, work / life balance, opportunities and prospects, stress / pressure?
This is a timely post, because I got a disappointing offer today from a firm I've been speaking to for a few weeks (they pursued me, btw, and knew what my existing compensation was).
I'm not desperate to move and not stupid enough to give up established tenure and all the associated insecurity for less, so when they came back to me with a package that's only worth about £2k more than I'm on just now, I told them to chase themselves (and explained why).