There are lots of factors to consider. I joined an early-ish startup as an employee (still < 10 employees). My previous job was Dilbert-esque, so this has been awesome. Working in the same room with the entire company is great. Sure, I took a bit of a salary/benefits cut, but it is totally worth it. I'm having a lot more fun, and if I'm spending 40+ hours a week somewhere, I'll take actual happiness over material happiness.