SLMG
M t M
The concept was ok and it was supposed to extend the flight time to get more 'handling' in per flight as opposed to the 2-3 mins in a MK3.
The problem was the 'launch performance' was poor and no doubt it was not helped as it got heavier. The BGA clubs were also looking to have something that avoided the winch/cable issues at restricted sites.
They only really suited large airfields where an EFTO was less of a problem,as the ATC were used to a situation that a 'cable break' procedure saw you land on the airfield, as opposed to outside the boundary (in a field) as per normal ppl training in powered craft.
There was always an issue with climb as it really needed more power and the engines available at the time (VW) were limited.