I'm quite curious for that comparison, I found the J$s by far the most neutral of all mods/pads.
I think I did cut a few daming holes too much on my jerg pads though, the highs became too strident.
But even when I covered up some holes, the J$s still are much more forward sounding in the mids/high mids.
The marleypads are actually the most dark sounding of all mods/pads I used. Treble is very well controlled. But the high mids are still a bit more recessed than those of the J$s.
In conclusion, I'm very curious how the J$s sound in comparison with the newest and proper jergs.