This new caliber strikes me as an absolutely brilliant solution to a nonexistent problem.
The ballistics are so close to 9MM that the difference is negligible.
The capacity difference of 1 or 2 rounds per magazine is also negligible when compared to 9MM pistols that already have 10-17 round magazines. If one wants another couple of available rounds, a spare mag solves that issue nicely at substantially less cost.
The lack of selection and availability of guns chambered to accept the round and the very limited availability of ammo are absolute deal killers for me.
At this point I see it as a shiny object to play with for those with lots of time and excess funds on their hands. I suspect it will soon go the way of the .45GAP.