Mid-size market maker or small prop shop?

I have a strong feeling that within the next week I might get two job offers. One is a trader trainee for a mid-size market maker and the other is a junior trader at a small prop shop.

If the offers are relatively similar which position would you take and why?

A little background about myself: I am midway through a Quantitative Finance master's program (not from a tier 1 school).
My previous work experience is as an accountant. I am trying to move into the financial world.

I am definitely leaning toward one position over the other but since I'm not an expert in the industry I would very much like to hear other people's opinions.

Thanks.