First of all, you can get a refund, (at least I could) for 30 days after the date where I had to send in the deposit. Read the contract that they give you carefully.
Secondly, there have been a lot of posts on this thread about why SOMA is a great school - written by current students and other applicants. Actually, for me, posting on this thread about SOMA's program was a really helpful thought exercise; writing down the facts and my feelings about the program helped me to rationally think through the choices that I had to make. It would also help to know a little more about your first choice school. So go back and read others' posts, and also, here are a few more things to consider.
1. SOMA's curriculum is unique. Can you see yourself being happy taking classes over the internet, juggling clinical experience, basic sciences, and studying for Step 1 during year 2? It may be the best choice for you or you may be happier with a more traditional school.
2. SOMA's people are unique. I can't wait to meet my classmates - as someone here on SDN put it - "I feel so punk rock for choosing this school." The facilitators that I met at the Brooklyn CHC were energetic, excited about what they were doing, and there was definitely a sense of communal purpose. Now there will be gunners and arrogant professors wherever you go, but I think that SOMA tends to attract altruistic people and repel selfish types.
3. Are you more comfortable with an established structure or are you happier feeling like you can be proactive about your education? One of the most appealing things about year 2 for me, is the opportunity to network with people you may be working with in residency or as a physician.
All that said, if I had gotten into my state school, it would have been really really difficult to pay $20,000/yr. more for SOMA. It kinda makes me happy that I didn't get into my state school, though, haha. Good luck at your interview and making this decision.