[smuzz]

Thanks Dave - that fills in quite a few gaps.
I've done some extra reading since that post (yes, got the order back-to-front there) and it seems that the linear implementations also dissipate more power at the top end of their operating range and therefore require a larger heat-sink - which is of course sub-optimal in an aircraft, but probably less of an issue in an RC car or boat.

The machine that I'm presently putting together (see below) doesn't have much space in the fuselage for extra batteries, unfortunately. The reports on RCGroups suggest that it comes with a marginal 50A ESC, so I was thinking of either adding a BEC, or a new uprated ESC, or perhaps both. It has eight servos, which is a big ask for the sort of integrated BEC you'd expect to find on a no-name ESC (not the one you're using, obviously).

I might get one of the HK UBECs that are rated at 5A and do some bench-testing on it to see what it's really capable of. That will give me time to do a new desert paint-scheme on the Stuka beforehand anyway. Thanks again!

   
Mean looking SOB!