It's a big commitment, active or reserve. My only advice to you is that if you do this you do it for the right reasons and think of the benefits that you do accrue as bonuses, but don't expect them.
Talk with a coast guard recruiter and find out exactly what you are or are not eligible for. If you do sign a contract make sure you read it multiple times and that whatever you discussed with your recruiter is listed on that contract right there and then.
Edit: Coast guard boot camp is pretty demanding -- more so than Navy or Army. Unlike Marine boot camp, I've heard it focuses more on practical skillsets than just strict discipline and marksmenship. If you enjoy maritime activities, you will definitely find the challenge rewarding.
By the way, here is the article where I learned about the Patriot Express loan:
For what it's worth I really enjoyed my bitter time in the military, it influences every single aspect of my life. Once you cross over you'll the world in a different light. A lot of the vets here on YC apparently don't share what I feel. Like a poker game it's all about the cards you're dealt with and trying to make the best of it.
Being a Coastie looks like a rewarding, challenging life, but it ain't gonna be easy!