To sum this stuff up...it appears there is no advantage to updating to FRG22D. (I already have FlashPlayer) if someone is on a custom ROM FRG22D would nullify the ROM more than likely unless the builder had it setup to run on 22D. I understand EasyRoot and the other one-click app will not work on 22D so someone would have to do the other work around to root. As of right now it would just be better to wait if phone is rooted and have FlashPlayer etc. than going to FRG22D. Did I hit that on the head? Just a few replies will suffice.
While I do not want to contradict CK (as he has the ability to send me to oblivion), the advantage I see to 22D with regard to market is having flash and other google apps installed properly. By properly I mean with the ability to get automatic market updates. I had the original FRF22 installed, but quite a few of the newer google apps and flash were via manual install, with no market link.
One other point is that CVPCS reported (more confirmed) that there are indeed a couple of different files as they relate to gps and wifi. So, if your phone is running fine on all points, and you can live with keeping manual track of some apps, then you are probably good to go.