Yes, our Stake had our Troops, Crews and Teams all registered individually, luckily I didn't have to deal with the recharter headache but from what I heard it was a real pain.
We had the same mass migration, my understanding is that the boys were co-registered sometime in August or early September in the Crew and in the Troop, they weren't sure at that time what they did with the leaders records but our advancement person was going to manual register us as ASMs during recharter to avoid any possible issues.
Your experience with how the Crews and Teams ran is exactly as ours, we were really a Boy Scout Patrol running as a Venturing Crew, we did (do) high adventure activities, went camping, and generally caused trouble the only difference between us and our younger patrol was they focused more of their weekly activities on merit badges where we focused more on career building and skills. I have yet to see an LDS Varsity Crew implement the varsity program, I heard rumors of someone trying to do it once but I'm pretty sure it was an urban legend. Our Venturing program in all reality isn't really focused much on scouting at all, most of the boys, at least now, are either Eagles or have no interest in becoming eagles. They seem to focus mostly on career and skill building activities.
I think what most people don't realize is that the actual change for most LDS unit's won't be that much different from what they are already doing. If a unit is strong in scouting they will continue to be strong in scouting because it's a way to fulfill the objectives of the Church for our Young Men. With the changes I think the Church has just given us more options to help fulfill that goal. If a unit hasn't been strong in Scouting it will hopefully give their leaders more options (insert my 2 cents and my unit on unit blood bath skills but if they couldn't pull off Scouting they probably won't be too good at pulling off the Church's activity program but what do I know...). It also stops us from having to register every boy who's on our records, for those of you who don't know the Church automatically registered every young man who was of scouting age into the scouting unit whether they had ever attend a meeting or not, whether they had interest or not, whether they had ever attended church or not.
The biggest concern I have for the transition is for the units who either stop the scouting program all together for the older boys (which is not how I read the instructions from our leaders) or decided to pick and choose what they follow. Our unit has decided to follow the GTSS (that's the right acronym for Guide to Safe Scouting right ), I'm envisioning a lot of units picking and choosing, saying this is a scouting activity and this is a YM's activity thus trying to skirt the safety rules. I think that will open a lot of risk to the youth and a lot of liability for the church until they come out with some more detailed guidelines. (I will admit however that it would be nice to have some more freedom with shooting activities).
Yep, I'm down here in the SVMBC, Quicksilver District. Not the most experienced Scouter in the world but trying to learn something new every day.