I know you're asking about J66-GT, but my J66-GTV just arrived this morning. Too soon for an in-depth review, but I can say that it's gorgeous in-person. The edges are already slightly fraying right out of the box. As expected, the reverse seams + intense color = brilliant showcase for the detailed geometric patterning. I'm a "Smedium" and I ordered size S and I made the right decision. The pockets don't seem to have that ugly flare out like they do in some of the product pictures. There's just enough room for light layering, but it doesn't look boxy or oversized like it would have if went size M.
Things you can't tell from the lookbook on their website -
The primary zip is actually an EscapeZip.
The shade of volt matches the heel of the AVM-007
Weight-wise it falls right in between GT Pro and WS
As with the J1A-GTV, there are no internal jacketsling loops