.........and they both have their inherent problems. The Rocket has had some teething issues (but Triumph has stood behind the issues and handled them, at least in my case). The GS infrequently breaks rear drive castings.
To make a statement like the GS is capable off road is pretty generic. If I was going to be really serious, I'd get a KTM over the GS. Me, I'm too cheap so I have a KLR, which actually comes with aggressive tires stock.
They are 2 different animals (the GS and the R3). The GS with Anakee's is a capable road bike but it will never be a heavyweight tourer like the R3 and the power isn't there. I know, I ride with a good friend who has one.
If you want to go to Alaska and ride up the Al-can, the GS is the ticket. If you want a heavyweight tourer, the R3 is the ticket.
Just buy the R3 and go out and get a used, late model KLR for a couple grand, install a set of D606's, the 685 Schintz kit, a Thermo-Bob, SW Motec engine guards and skid plate and call it good. That way, you have 'em both and 2 bikes to ride.
There is another poster on here that has 2 like me (KLR and R3). I'm sure Ugarte will be chiming in somewhere along the line.