I may have figured out why MMS isn't working. When I got the new memory card I put it into the phone (a 2.3.3 build with MMS nonfunctional), then I copy/pasted my old memory card to the new one via my computer. After that it was a Ti Backup, then the new ROM (yes, I did all the wiping except for SD card). When I was restoring things with Ti I thought I was being pretty careful - only restoring data for the updated apps, and only restoring apps+data when it wasn't already on the phone. I didn't even restore anything related to system settings. Could I have somehow imported the wrong thing that somehow jacked the proper settings for MMS? Perhaps Handcent?
Hopefully calling Virgin to restart service is going to fix it, but if not my solution is to wipe the card completely and start from scratch. Save a FEW things manually, like my contacts, bookmarks, music, pictures, swiftkey3/Swype info, etc... but basically start fresh and reinstall all the apps from the wild.
However, since this is just the interim until I try CAI I'm going to run it for a bit longer then switch out; MMS isn't my primary concern at the moment. I absolutely LOVE the battery life with Mirage. Right now I've got my phone in marathon mode. I'm at 25 hours unplugged and 91% power remaining; this is with NO data/gps and a mostly-constant signal. No live wallpaper, no animations. 51% standby, 47% idle, 3% display. 3800mah (supposedly) battery. Tomorrow is the real test when I'm at work; I'm in and out of coverage regularly, usually have music playing, and spend a lot of time using the data connection. Compared to my old setup (with the same battery) it seems to be noticeably more frugal on the power. Then again, it may be because I got rid of google goggles just yesterday when I found it was sucking down roughly half my energy even after it'd been closed.
I'm looking forward to CAI - I saw a video highlighting changes between GB and ICS that showed a feature to restrict data transmission by program. I don't WANT my game scores to be uploaded to a central server (or most of my other information, for that matter).