One further thought re training/familiarisation - a lot of motor gliders are NOT short field machines. They are generally underpowered light aircraft, that get their performance from low drag.
The low rate of climb can bite you - beware high temp, high pressure altitude, and high humidity. You don't have a huge margin to start with - if the conditions knock 25% off performance, you will notice it much more than your average GroupA machine.
Throw in a light or nil wind and its effect on climb angle....
Watch the TORA and TODA!
Having said all that, I think they are great fun ... go for it.