I had 17" on my 1150 and used the same pressures as the 19" wheel.
Handled fine and much quicker steering, when you put the 19" back on it feels like a barge for the first few corners and much harder to turn in.
Used Metzler Z6 to start with, very good wear and handling, and then Conti Road Attacks, good handling but wear out in less than 4k miles.