Ok, so bought some of the 20A ones off ebay to run my featherweight, and they worked fine...

... after replacing the microcontroller with firmware that worked, upgrading (adding) the noise protection, and fitting heavier duty cables...

The firmware had a feature/bug which meant that you could go from forward to reverse just fine, but if you tried going from reverse to forwards, it would do nothing unless you held the stick centered for a second or so, and even then it only sometimes worked. It also didn't turn the motors fully on when the stick was at maximum throw. To fix it I modified the code used for my antweight ESCs, and carefully fly wired in the replacement microcontroller chip.

The cables were also pathetic, and got fairly warm even when running drill motors under no load, so I replaced them with cables of double the thickness. Also added an input capacitor which should have been fitted and wasn't, and beefed up some of the tracks to the MOSFETs which looked a bit weedy.

It's a classic case of the chinese reverse engineering a good design in the cheapest way possible; the circuit used is actually very good, but the implementation was lousy.

They now work pretty much perfectly, but were hardly plug and play! Still, not complaining too much; £13 for a featherweight ESC is fine by me

Firmware upgrade wired in (old chip shown next to the board)
DcvKDBQ.jpg

Cable upgrade and noise suppression (bottom board is the original)
2WSmRZo.jpg


(These were the ones I bought: http://www.ebay.co.uk/itm/RC-ESC-20A...item3f363a2e2a )