FYI -- My T-Mobile SDA, which is flashed with the newer iMate ROM, didn't seem to like this update. The iMate ROM is so much better, with exception of the more frequent 'searching' thing, that I had to upgrade. Will probably re-flash to T-Mobile if and when they ever update the ROM for the SDA.
Couple things I ran into with this radio update:
Problems with CityTime Alarms program. After flashing this radio update, I would frequently (but not always) get a 'cannot load citytimealarms.exe' error upon bootup. Uninstalling and reinstallikng CityTime Alarms did not clear up the problem. It did not happen before the radio update and has not happened since re-flashing with the iMate ROM and not re-applying the radio update.
Calls-dropping -- a new one. While it did seem that my phone was doing less 'searching', I was dropping calls frequently, even though I appeared to have a strong signal. This isn't something I ran into before the radio update.