[Ask HN] Move from consulting to full time employee in a startup...?

I'm an engineer and have worked 10 years mainly in development and ICT.

Last year I worked for a startup as a freelance and ended up earning some shares as there was not enough money to get paid.

Now, I have the possibilty to be hired in this startup (which has just received money from Business Angels) for 20% less than what offers my daily work (in a consulting company) + a possible 50% bonus each month starting mid-2012 (if the startup makes benefit).

The thing is I really want to quit my consulting company and I have several options: go into another consulting company (some are better than the others... at least I want to beleive it) or working into the startup (which I know owns 7% with some additional stock options yet to come). I tend to think I will learn much more in the startup, but that is a high cut in the salary (for a dad moreoever).

Would you have any advices ?