i got 05 dj II's.
Same as DJ I's except yours have external rebound, mine have internal.
Great fork, solid, perfect for urban/dj, work well trail as well.
I do not see why you would want to change them over, unless you have oodles of cash.
.
They won't be any lighter than what you have but, will be built even more solid than your previous pair. 20mm axle will be alot stiffer than ur QR on dj III's.
Give them a try then change, then you can at least make a good comparison of then products for future preference.
Cheers,
Ken