I do love the Jac. I was hesitant at first, because I figured I was just lusting after the new shiny, and really I have enough mods -- but I'm so glad I got it! I have more expensive mods, but the Jac just feels the most luxurious and pleasing to me. The soft rubberized coating is oohlala.

The honeymoon period has worn off, so by this time I should be sort of ho-hum about it, but every time I pick it up, I'm all

!
It's my favorite by a high margin, but I should mention that the fire button is *very* sensitive, which could be either a benefit or drawback with hand pain. Benefit is you don't get that thumb joint pain that comes with a lot of the smaller more resistant fire buttons, drawback is if you have to hold it awkwardly / carefully to avoid firing by accident. I'm completely adjusted to it now, and don't have misfiring problems, but it's worth mentioning because I could definitely see it being a problem for some.
The battery-in weight is about 165 grams, compared to Pico 75W's approximate 135. So, weight is about the same as an eVic Mini v2. The more slender design feels is less bulky than the Pico, though, and the curviness feels much more comfortable and pleasant than the eVic mini.
As Katdarling says, the Jac probably the closest thing to a tube mod in box mod form: the height is the same as a Provari Mini, and it's about 1.5 centimeters wider.
(I'll also add that the finish is gorgeous, but might not work well as a pocket carry with coins, keys, etc. or carried loose with other stuff. I expect it would get scratched and dinged, but I haven't subjected my precious to such cruelty!

)