I have this beauty now on my desk:
I used a preliminary OS image from Radxa to check some stuff by running sbc-bench -r: sbc-bench/results/reviews/Radxa-Rock-5-ITX.md at master · ThomasKaiser/sbc-bench · GitHub
Forget about the performance numbers present there since there’s something wrong with DRAM initialization. While the two SK Hynix 32Gb LPDDR5 modules should be faster than the LPDDR4X on Rock 5B (4224 vs. 5472 MT/s) memory bandwidth hasn’t improved and latency is worse compared to LPDDR4X.
The good thing to report is that the board is lying flat on a table at 23°C ambient temp with neither heatsink nor fan and not even the rather demanding cpuminer benchmark led to throttling since temps remained below 76°C 
As for the hardware just as quick addendum to sbc-bench -r info collected above: there’s a Genesys Logic GL3523 USB3 hub on the board and also a Terminus Technology Inc. USB2 hub.
Idle consumption with all governors set to powersave and nothing connected except TF card, the (optional) PoE module and one Ethernet jack at GbE speed is 4.00W according to my ODROID SmartPower 3 (5.3W with governors set to performance).
But just like the benchmark scores above this is BS at this point in time since settings haven’t matured yet.