I have a lowered GSA and come from a standard GS, handling wise I would say there is no difference at all.
Riding position on a standard GSA to a lowered GSA would be the same too as the height reduction is made via the suspension
The only difference I have noticed is the pegs touching down, not all the time but only when I am cracking on a bit, usually on good dry days and decent roads
The way around this for me is to take things up one notch ie, for rider only I ride in rider plus luggage and if loaded I ride in luggage with passenger, this takes things up just enough to sort ground clearance but not too much to affect my feet being on the floor when stopped
I would imagine at your height though feet on the floor would'nt be a problem with a standard height bike
For me though the lowered suspension is a god send, so much more confidence when coming to a stop
