Decided to take the plunge today and try OMGB.
I figured I would relate my experiences in case anyone else has similar stumbling and fumbling.
Installing the rhodimg.nbh took a couple tries, something about the first 1GB SD card I chose was not liked by the boot loader. The second 1GB (also Sandisk, identical from all appearances) worked first time out. Go figure.
Once I got that rolling I couldn't attach to the phone via adb/fastboot. Windows was popping up a "new device" dialog, so I figured it had to be driver related, even though adb (and droid explorer) work with FRX7.1 without issue.
I ended up editing the Google/Android USB driver to add the VID/PID (18D1/0001) that was shown in the device manager and then allowed Windows to "re-install" the driver. Now I finally have access to the phone via fastboot.
Using fastboot to install the recovery image was a breeze, as was getting OMGB 1.2.3 installed from within recovery.
Booting OMGB went surprisingly fast, I waited for the system to settle out before rebooting back into recovery to install Gapps.
Installed the full (20mb) gapps.zip and rebooted. When I got into OMGB they were nowhere to be found. Rebooted into recovery and tried again, but still no sign of gapps when I went back into OMGB.
Back into recovery, wiped the cache and data partitions, booted back into OMGB and again waited for things to settle out. This time into recovery I tried Vzi's minimal gapps and it worked.
Are there any known issues with the full version of Gapps and 1.2.3?
My next stumbling block (yet to be fixed/understood) is that Market from vzi's minimal gapps is FC after a short time. It loads, sometimes search works, sometimes FC. I managed to install one application (Zeam), but that seems to be about it - too many FC to get anything done.
Should I try 1.2.2 since it's "more stable", or is there something I can do to fix Market in 1.2.3?
Next question is in regards to APNs... it seems like they are not fully working - I set it up and click "save" but the APN doesn't appear. I need to use an APN to get MMS working with Boost, so if there is anything I can do to help debug why it's not working let me know. I'm guessing this is an artifact of needed GSM support...
Also, I can't seem to reboot into recovery from within OMGB (via the power down menu choices). The phone just appears to freeze, I end up pulling the battery to get it to reset.
All in all I have to say I'm quite impressed. If I can get Market working (so I can install a couple of apps I really use a lot) this will be awesome.