Just out of frustration, I went the GoldCard + RUU option on my branded T-Mobile Desire this morning.
Haven't noticed ANY speed increase (I thought this JIT thing was supposed to make it faster?), and few of my apps gave me the option to install to SD card. Those that did, did install fine there but often the icon went missing/replaced with a default one.
What I HAVE noticed is that since the update, I have missed no end of texts and calls. It's worse than my old Hero/G2 was on T-Mobile with missing calls and texts.
Oh....I also don't seem to be able to go back down to 2.1.....gives me a bootloader error message.
I guess this COULD be one of the reasons T-Mobile haven't released it yet.