No personal experiences either but let's do some quick calculations :
Stock tire: Width: 150mm Height: 60% of width = 90mm
Other tire: Width: 150mm Height: 70% of width = 105mm
That's 15mm difference, when you apply that height on the circumference, putting the 2 tires on the floor side by size, you'd see a 30mm overall difference in height.
Clearance wise, the only part I can think about is the inner mudguard (which is a different part on the R than on the GS), but just looked at it and it seems it will accommodate an extra 15mm without issues.
Last and more unknown variable is suspension when fully compressed: the tire will be 15mm closer to the frame/underseat area, but not likely touching anything

- just a guess, no calculation here

and like bbbelanger says, if frame/suspension/swingarm from GS are the same size/geometry than the R, then this is not likely to be an issue.
Seat will be a little higher and bike will lean a little more when on the side stand, but nothing drastic. Handling of the bike will likely feel a bit different too. You'd leave the front tire stock ?