I too have been having serious problems with a 60/120 pair bought recently - clear design errors, particularly in using a 6% efficient leadscrew, leading to the need for high currents and large batteries and the risk of going flat See my postings on http://www.modelflying.co.uk/forums/...91&p=2#1218304 for full details.

I am not prepared to put these in an aeroplane as I cannot even get them to work reliably on the ground - and my first RC retracts were in the late 1960s!