Thanks for adding an academic perspective on what is mostly an industry-centric discussion :) I struggled myself with choosing work at a startup VS going for a PhD after my Masters, ended up taking the job. I love it but still think about going back to school every once in a while. I miss the whole experimental side of academia, having loose goals and being able to fail miserably without risking somebody else's investment.
I decided to build a career in academia after working as a technician for a college that afforded me the freedom to experiment with approaches to my work. Now I am an IT manager at a small state University. My boss allows me the latitude to approach projects with creative perspectives. This fall I also plan to begin teaching, and I am continuing my work towards a Master's degree. Lastly, I find the structure of academia to be such that my off time is clearly defined (at least in comparison to working for a company in private industry), and I am able to also pursue entrepreneurial ventures.
The pay check may not be as good as working in some companies, but working in academia provides a lot of freedom to try ideas, do it your favorite programming language, go to conferences, and visit far-away countries.
Academia is certainly not a good option for everyone, but it's certainly something you could consider.
That said, I don't exclude the possibility of going to industry again later.