I was led to believe that the Hex S (RB760IGS) achieves full gigabit throughput. This is not the case with IPv6. Due to the lack of IPv6 fasttrack support, IPv6 throughput maxes out at roughly 500 Mbit/s. That alone is bad enough, but on a DS-Lite connection, IPv4 is tunneled via IPv6, so even IPv4 throughput is limited by the lack of IPv6 fasttrack support. To test that this is indeed the cause of the low throughput, I disabled all IPv6 firewall rules. This allows the router to use fastpath acceleration even in absence of fasttrack support, and indeed then routing IPv6 at full gigabit speed is possible. But what good is that without any firewall capability?
Please add IPv6 fasttrack support, urgently.