One more proof that startups are for people that are into the experience. Not the money, not the credit, just the fun of doing it. If you're about calculating your percentage, figuring out if your're getting paid the largest sum of money around or have the best title - talk to the recruiters of big cos.
Totally agree with you. While you need to fairly sure you are on a path that is capable of providing you with a decent return at some point, the fact remains that you have to absolutely love the journey, otherwise there are a lot easier ways to earn a living... I'm involved in my third startup experience (one decent-ish consulting biz (not really a startup but a new biz nonetheless), one ecommerce biz that went fairly big (in UK terms) and then blew up, and now a social commerce play), and I still get the same feeling of being a kid in a candy shop that is just not present when you are doing (much better paid) work for other people.