Roadsmarts after 8,000km
Here is my experience with Roadsmarts after 8,000km trip to Portugal.
Bike was loaded with my wife and luggage for two (around 190kg load). The roads we covered were 60% A/B roads and 40% highways (from which around 1,000km on German autobahn cruising around 150kph to 170kph - that eats rubber a bit faster).
When I had Roadsmarts fitted I was surprised by quicker handling - not sure whether it was due to pointier Roadsmarts or my old Battlewings were being slow after usage by the previous owner. I can make the bike lean into the corner much faster.
I had Roadsmarts fitter to my previous bike (Triumph Sprint) and they proved to be excellent on GS as well. Grip is excellent dry and wet and they are also very stable at high speeds (tested up to 190kph).
They will still do 1-2,000 km. Front tyre is still good for another 3-4,000km but the rear is not going to last that long. This is mainly due to fast riding on the highways.
I think it is great road-only tyre and with lighter loads or more A/B roads use the life can well go over 10,000 km.