ZZR is intended for the longer rides, not quite the HP of the 12R but same block and potential.. except i htink the ZZR is carb'd still. The ZZR has a more upright position, you may not fele the diff in a 20 mile ride but a 6 hour one and u sure will. And most likely the passenger pegs are lower and more comfy for the 2 up rider as well....if u ride long and alot.... go ZZR if you prefer the ultimate in performance (Straightline at least) look 12R. Course once u hit a corner a 500lb wet bike wont handle like the 6R, thoguh if u are looking for a 1200CC cornering should not be goal number one...The zzr looks good and is practical, if u like it go for it. I'm more into the all around bike the the Z1000 fits the touring bill better and still aobut 100lbs lighter,(once u ditch the 40lb exhaust) so it handles like a smaller bike, and is geared LOW so itll hold its weigh with most any sport bike till 100 or 120. if u want to race over 120 then go the 12R.