Hi, Here are the physical differences between the Jem frets
The 3 different sizes of fretwire on JEM's are generally 6105, 6100 (Jumbo) and 6140 (seen on the UV's, the JEM777VDY, and the BFP)
This is the size from the fretboard, height, and width
6100 .110 wide .055 tall
6105 .090 wide .055 tall
6140 .106 wide .039 tall
Some Jems have what is called SBB216-195 fretwire, it is also what is used on the RG series, best I have come up with, is it's specs are the same as the 6100, possibly the 6000 which is just a touch bigger than the 6100.
The common ones are 6100 and 6105. The 6100 is common I think on all of the old neck joint jems (excluding those listed above)
that page will tell you what number was on what guitar.
Anyway, the long and short of it is, the 6105 will be a smoother feeling fret as it is narrower, and the crown will be more exaggerated than the 6100. But, the downside is, they will wear faster since they are narrower and have a sharper peak. The are the same height though, so overall general feel shouldn't change much. I personally prefer the 6105's, but when I do scallops on a neck with 6105's, I leave the seat wide enough to accept a wider fret at a later date if so desired, because the 6105 will wear slightly quicker.
So, personally, I would say the fretboards feel pretty much the same, but the 6105's might be a little smoother for a while, though, I don't notice much of a difference between say my VWH and my SK, the UV's on the other hand feel much different as their frets are nowhere near as tall as the others
Hope that helps