I think I've asked this to friends that have done it, but can you always go back to the way it was before jailbreaking?
I have a Nook Color that I rooted and put Android Gingerbread on. I enjoy modding that because if I brick it, oh well, no big deal. My phone, however, it a litter different. I don't have a back-up for that, and if I screw up my phone, I'm now without a phone. Technology and I don't get along, it doesn't like me very much. I tend to break things, lol.