Everything works on 2.2.1. For now, you can not say that for AOSP. They just got MMS working a couple weeks ago, which was a big plus. And better battery life on a 2.3.3 rom? I don't think so... Least not yet. It has gotten better, I will give you that. But a 2.2.1 rom's battery will last longer, under similar test. A great info thread on this is here, by mmarz (also linked in the sticky Reference thread).