Hello Sandybandy,
I don't unfortunately have any answers to your specific questions, but i'm very much interested to hear if there are any answers forthcoming here, so i'm subscribing to your thread.
I agree with MightyMouse's recommendation.
I'm not convinced that there is a black or white solution even though Triumph market the two models with nothing in between or an option to specifiy the ergonomic set-up on either models from new.
The solution lies in the individual riders shape & size, physique/posture & riding style etc...
With this in mind, I also recommend that you take things in stages.
I didn't really enjoy the feet forward set-up for a number or reasons so have opted for the mid controls but the 'R' bars are definitely not for me so i've got the touring bars and that feels like an acceptable halfway house. Definitely worth a try IMHO.
My ideal set up would be the mid mounts with a set of handlebars halfway between the 'R' and the 'GT'..........If someone out there fancy's producing them, i'm planning to be at the front of the queue....They will need all the GT electrical features built-in though.
...forgot to mention that I have both the 'R' & 'GT' seat and I much prefer the comfort of the GT seat compared to the R despite the higher R seat offering more space for my leg length.
Ergonomics is a complicated thing. I should know, I design vehicle interiors for a living among other things.