Guys,
I have about 10K on a set of Road5s. I too was anxious to see the GT version out, but for whatever reason M is moving slowly. At any rate, the standard PR5 is working well for me. I know that load rating is the issue with the non-GT version. For the 10K miles so far this summer it has been 30% high speed interstate, 40% normal city roads and inner city highways (rough roads in Seattle area) and 30% hauling ass on curvy blacktop in hot weather.
They have performed as well as I can recall the PR4GTs ever did. I ride single, 150#, ~22# in the each saddle bag, ~15# in the top case for a total of 209lbs. at all times. On a recent trip to Laguna Seca I had an extra 30# on the back seat making it about 240 lbs. total.
I would not hesitate to get another set of PR5s when needed in lieu of the GT version.
Safe Riding!
Gilbysan aka - Fat Ninja