I have about 15 hours / 300km on my neoboxes now, running sensored FOC 80Bat/100Motor/-15Bat/-60 motor without a fault or any problem VESC related. Never reached thermal limit on VESC but Southeastern Canada is flat 
. I would happily recommend the V4 as an available replacement for focboxes and in the future I plan to acquire some v6 neoboxes. Only issue that was really minor I had with the micro USB port is such a pain in the ass to use but there’s a technique and I’m at the wrong angle etc.
Edit I also run at about 55-59k ERPM, if that’s of any interest to people, no DRV faults yet.