That is until you turn up at the average GA airfield - and find you cannot
get between the markers, cannot turn around, simply do not fit!
We have a Taifun at my field, needs three people to unfold it - I refer to it as a
Perodactyl. One person cannot actually move it when in the hangar. Virtually
needs a gale or the curvature of the earth to get airborne. Lovely when flying
and murderous on maintenance and care when not.
We also have a Grob -
which is much more practical - buit still needs a fair amount of space and has
an engine which seems quite frail. Endurance is certainly not everything.
I think you are being a little unfair Gasax. Having owned both, I think that the Taifun is the nicer aircraft and that (if both were left rigged) a Taifun is probably more practical than a Grob 109, being faster for the same fuel burn. T/O and Ldng distance for the two aircraft are about the same.
However, you are right in much of what you say.The Taifun will cruise at over 100kts burning less than 15 ltrs/hr for well over 600nm but with a low power to weight ratio take off and climb performance is not stellar - although this can be remedied by fitting an uprated engine/prop. I like the Taifun but I have to agree that it is now outclassed in performance by many of the modern generation of LAA aircraft.
TMGs all have the same problem in that by definition the wings are big (a Taifun is 17m span). As you say this is often a challenge at GA fields where marker boards can be awkward. It is also a problem in terms of hangar space. The Taifun wings fold back which cuts down on space but as you say is a pain to rig for an hour's flying. I think you will find that the Grob is just as bad if not worse.
Added to that is maintenance charges. While LAA owners can do their own thing, TMGs with a type certificate holder fall under the EASA banner. This is eased somewhat by having the BGA act as a CAMO but it still means compliance with all the EASA bulls**t.
This isn't to say the motor gliders don't have a role - the new generation of powered sailplanes are fantastic pieces of kit for exploring soaring possibilities - not great for touring though.
It comes back to the old chestnut - decide what mission capability you need and choose the best aircraft to fulfil it.