I saw 165mph on the speedo on the Autobahn in 2007 but it is an analogue speedo so probably over-reads by 10mph up there.
This was with a stock 2008 model (still had those godawful Bridgepoop BT021s on it) with the screen fully down, both side-bags mounted, a 52 litre trunk and a 350lb Boomer onboard.
Theoretically a stock 08/09 is faster than the 10- models as the 08/09 are limited to 186Mph in the ECU but the 10- are limited to 155mph.
I have yet to hear of anyone comparing early/late model top speeds under identical conditions with calibrated speed measurement equipment.
If you really want to go faster, get a ZX14 or an H2.
Whilst flashing will give you a little more top end power, it's not a huge amount (10-15bhp) which may add 5mph to your top speed.
One of the things that is changed when they flash the ECU is to remove/raise the speed limit.
The primary advantages that flashing gives are
-low RPM grunt so she will accelerate harder
-less snatchy on/off/on throttle
-believe it or not, slightly better gas mileage.