Ask HN: Which career path to take?

Hello HN! I'm using a throw-away account, but I'm a long time HN reader and all the advice that I've read here has helped me become a better developer. Now I'm here to ask for your help. I know there should have been existing threads like this, but my Google-fu is failing me lately so here I am.

I am a junior developer, more than 2 years out of college and had some experience working for a startup as my first job. I was severely underpaid, and felt that the company was going nowhere fast, so I decided to look for greener pastures. I have been getting interviews, and so far all of them have been positive. Not that I landed offers on all of them. They liked my attitude, but was disappointed with my experience.

I have a few offers on my hand though I have a tough time deciding which to take. The top two choices being:

1.) A startup with a product that looks interesting, small team, poised to grow in a few months, full of bright guys, seems fast paced. The problem is the salary is below market rate (not as abysmal as my first job though), shares that won't make me rich (maybe enough to buy me a Macbook if they get lucky), almost non-existent benefits. I accepted this offer by the way.

2.) Then came company number 2. More of a consulting job. No core product. A quite large company servicing big-name clients. Smart team (maybe not as awesome as company number 1). Seems to be quite agile with regards to work. They offered me a market rate salary, with benefits that would make anybody drool. The problem is that you fly from project to project, without actually having something to call your own, which makes stuff less interesting.

I know that I should go for whichever company that offers the best experience. Frankly, being junior, I stand to learn a lot whichever company I choose. Technologies used are fairly equal and modern, with company 1 being a tad bit cooler, and company 2 being a couple of notches more enterprise. I'm leaning towards company number 1, since I'm more of a startup guy (I'm on HN after all). The rest of my family and friends think that I'm crazy for not going for company number 2. There's also the issue of retracting a job offer that I already accepted.

What are your opinions regarding this? I mean, I could go for company 1, but the practical side of my subconscious keeps nagging me for 2.