JP3-JP5-Hawk
I think it very much depends on the individual. Having gone through the 'Green Shield' system I don't know much about the JP3 but I found that the BFTS course, including Gp1 Phase1 was pretty much a re-run of the UAS Bulldog course and, being the idle little sh1t that I was, I did the min possible to get through.
The big jump and major shock to the system was the Hawk course at Valley. I spent the first half of the course effectively water skiing behind the aircraft and had to clean my act up in a very big way in order to pass the course.
Whether it's an aircraft change, role change or whatever, a shock to the system like that does a chap a power of good and instantly dispels any notion that one is the ace of the base.