Personally, I'm using the leaked 4.5.0.44 and it's working fine for me. I switched to YouMail, so the MWI isn't an issue. I still get the missed call icon, and that's enough to alert me to check my email for the voicemail. I'm finding battery life to be pretty good--much better than on 4.5.0.37. And the memory leak is about the same as it was with 4.2, so no big deal. In fact, I've found that free memory fluctuates down *and up* in the course of a day, although the general trend is down. If it means I have to do a soft reset every few days, that's no trouble. I was doing that anyway with 4.2. I believe I'll keep 4.5.0.44 until I either find some terrible bug or until there is an official T-mobile release.