I've got the 20mm ones from Norman's on my 800GS, they were fine and needed no cable fiddling at all - I also rotated the bars very slightly forward, much more comfortable!
One thing to be aware of, I've got Barkbusters on mine, and a Puig screen, and on full lock, the handguards do touch the screen - only a bother when I'm putting the steering lock on to be honest, I need to periodically check the screen bolts to make sure they've not been jarred loose - lost one before I noticed that!!