I'm now back home after almost 3 weeks on the road.
The R80R have performed brilliantly!
The bags fits the T12 like a glove. Properly mounted they never budged the slightest even on very bumpy tracks.
Coming from hard cases I expected it would be more of a hassle to deal with soft bags - this haven't been the case.
I have never used a more convenient luggage system. Very easy to pack/unpack and getting to/stowing away things during the day was never a issue.
I carried everything I need to travel indefinitely: 7 sets of underwear (socks, boxers, T-shirts), cold weather gear, camping gear, tools, sportswear (including running shoes), pc, camera gear etc.
Even without the 2 x 4L aux pockets I had just enough room for everything.
I believe that I've found the perfect luggage solution for my needs.