Interestingly this device has a Cavium 7010. The tested VPN throughput seems lower than what the HW is capable of...
1 core :O, as i keep complaining why is anyone using these cavium CPUs keep using old setups? What about their 32 or 48 core MIPS variants? Ubiquiti wont be able to compete with mikrotik in performance if they keep using dual cores. Other VPN router manufacturers also still need to consider using many core. Its not like the encryption engine is a per chip, its usually a per core thing.
In terms of UTM performance i would expect that chip to do around 100Mb/s or lower in throughput.
UDP has a lower overhead than TCP, so manufacture VPN ratings are typically higher than my measurements.