I am 6' 0" but with a 30 inseam.
I started out with a little Honda 200, then to a Yami XS650, then to a Kaw KZ750 with wind jammer and full luggage.
Then I took 25 years off from riding a bike and jumped back in with the 88 Standard that I have now. Even after the 25 years off and never having this big of a bike. Picked it up at a dealer and within 2 miles was on the interstate to ride home. After a couple days in a parking lot near home to get used to how it felt, I was good to go.
As long as you are sencible there should be no problem learning the heavier bike. THE big thing to remember is that if it starts to go down, do NOT stick your foot out like you did on a dirt bike, 900 lbs will break your leg, just let the crash bars do there job and try to pick it up quick before any one sees you.