Was just talking about this with a post-doc in the lab I've joined. He was saying there's poor and then there's poor. Without downplaying the fact that post-docs are underpaid, there are many benefits. You get to work on something you're interested in; in many labs you have almost complete schedule freedom; you typically have good medical benefits, etc. So there's a lot of freedom. As in industry, a lot of the experience depends on whom you're working for, but moreso due to the recommendation requirements and power differential. If it's a bio-lab that expects butts in seats pipetting 9-6, that's outside of my experience.