Have any officers transferred from NG to USAR and what was the process like?

Well Sir, I had to ING transfer to our USAR unit, they had to go into the IRR or something then the recruiter pulled them out and placed them in our unit, both were Captains at the time.

I transferred this past summer. The process took about 6 months from when I dropped my packet. It went pretty smoothly but a couple things fell between the cracks. I agree with Yinon that admin support on both sides in important to make sure everything is in place afterwards - I've been in the Reserves since August but just this past week I had an issue that required me to reach back the Guard for help.

I have. It goes exactly like you would expect it to. A total mess. The two systems don't talk to each other at all. So the biggest factor is how good the admin support side is on the gaining and losing unit, and whether you have to chase them for everything or not.