Getting back to the orignal question.
Cockpit ergonomics - nice and roomy although I have found the 2C can be a bit tight around the shoulders if you've got a heavy jacket on and intend going wave flying/ridge running in winter.
Handling - its a Discus, with the caveat that if the engine fails to start and for good measure then fails to retract you've got a plastic K8 - however if your like me (mechanically challenged) getting the engine out in plenty of time and remaining within reach of a suitable field should it all fail generally you should have no problems.
Like all Sustainers it is very noisy in the cockpit with engine running and I would consider taing a pair of ear plugs/defenders with me if one was to contemplate a long session with the engine running continously.
Hope this helps
Bletchleytugie
Windrushers Gliding Club
Bicester