Would you jump ship in this situation?

Current firm: Small, industry-specialized consulting firm. Great leadership, good culture, good upward trajectory, and I'm well respected. Been there 4 years. If I left, company would be dealt a huge blow due to small size. Some very real concerns about the future of the firm (PE owned, and they're tidying up profits for a sale, and bonus this year was miserable even though performance was OK). Total comp 200K.

Offer: Larger, industry-specialized firm. Hit or miss leadership (some real good eggs, some total dicks), OK to questionable culture, good upward trajectory, but I need to re-establish myself (which I'm confident that I will be able to do). Firm is in a rebuilding mode (got acquired 2 years ago, a bunch of partners left, and now they're hiring senior level folks like crazy). However, acquiring firm is also owned by a PE firm, and they may also be tidying up for an IPO (so realization of bonus potential is up in air). Total expected comp $240K.

What would you do, and why? Am I whoring myself out for $40K (aren't we all, in some respects)?