Combi-Brake is much like ABS - it's there as an assistance to normal braking, as opposed to be something you rely on. One lever does not control both brakes, it's more a case of both levers being able to apply some braking force to both discs - you still have to ue both levers to operate all the pistons on bothe the front and rear discs.
Like any rear biased machine (eg cruiser) the rear brake is your main brake. Unlike conventional brakes, the left lever whilst slowing the machine powerfully and securely, also bring about a portion of front end braking, which means that if you cover it in traffic you are able to easily outbrake the U-turning taxi.
Once out into the mountains/contryside normal braking techniques apply - rear biased machine, so rear brake is paramount, with front brake being used to control the attitude of the machine into bends and for strong braking.
I personally think that Suzuki missed an opportunity to devise a 'sporty' application of CBS for the 650. Honda got the balance right with the x11/injected Blackbird which although fitted with CBS it's hard to detect unless you really stamp hard on the rear brake - different to the VFR and carb-BB set-ups.
As the Burger 650 is so large, it is actully quite easy to lock the rear tyre in hard braking, which is criminal for a touring orientated machine. ABS or 'sporty' CBS should have been standard from the start.
