Take a look at http://cycle-ergo.com/
- you can input your height and inseam and compare ergonomics for various bikes. See below a picture of what it outputs for your specifications (2010 G650GS, not sure what you have).
They don't have the production Empulse up yet (I've submitted a request to them), but the concept definitely looks really cramped for a tall guy.
The production bike is significantly less cramped, but it's still a more aggressive riding position than your GS. Brammo's CEO Craig Bramscher is 6' 3" .. I believe he's stated somewhere that he's comfortable on the Empulse.
Putting your butt in the seat is the real litmus test, but until then here you go : )Up top, 2010 BMW G650GS vs 2012 Brammo Empulse (scales close but not exact)Below, 2010 Brammo Empulse Concept
*sets trap for Brammofan*