a user on the radxa discord quoted 18 Watts at the wall under 100% CPU stress. 4-5 watts at idle was a little bit of an underwhelming result, but it may be tune-able to get that figure lower.
I believe it has the same Heterogeneous Multiprocessing design from cell phones, a combination of low-power and high-power cores, which helps a lot in terms of power efficiency especially when the software can take advantage of it.
Anyways, it's happening. The meek little SBC has grown up, it's a Real Computer now. Yes, things like graphics drivers and virtualization support are surely lacking. And it's not $35 any more. But as an affordable server platform for linux-based apps and containers, these little boards just keep getting better and better.
Small server part of the pixie.town infrastructure. Registration is approval-based, and will probably only accept people I know elsewhere or with good motivation.