yes mine are 3" and it does make a big difference also i have a fill 2 inches of cone travel. also the length of the coil also helps to dissapate heat. JL rates their subs very well. they will take just about exactly what they rate them for.

my subs ratings are for the power mouse boxes i use them in. the wattage rating would be less in a sealed or ported box of average size. this is because my subs are effient and dont need all that many watts to reach full cone excursion in a larger box. for example my 10" subs are playing in .4 cu ft for the sealed side of the BP box. but im still hitting usable frequencies of 27 hz and still audiable bass output of 10 hz the reason i use 3" coils is because any other coil would fry in a box this small.

i have not read much on the new JL V2 subs yet but i was told or i heard someplace they were basically the same as the older versions but they just look a little different. i cant say for sure i could be wrong.
i think ill go to their website and gather some info so i have a better opinion on the subject.