I've had mine at 1 1/4" from the top of the tree to the top of the tube (stock/recommended is 3/4") for some time now and I like the quickness it adds to the steering without losing much in the way of stability. A word of caution, though; if your front suspension preload isn't cranked up and you have stock fork springs, raising the tubes will cause grounding of the bulge in the fairing in bumpy right-handers or the sidestand in lefts.
'07 CPB Blue; ZGST windscreen with MRA X-screen adjustable spoiler, tube bar adaptor, PC III, ATRE,BMC air filter, modified stock seat with 2nd Look cover,Scorpion Flame Ti slip-ons, Galfer rotors front and rear, braided-stainless lines, C-F 10R front fender, C-F hugger, C-F inner fairing panels, painted foreman's fins with faux C-F inlay, polished rim lips wired for heated gear and accessories, Givi V35 side bags and E41 topcase with SW-Motech qd mounts