The ones that fit on top of the dash are perfect-- easy to see, rock solid fitment, i had a zumo 550 mounted there which did not foul screen in its lowest position so a 660 should be okay, easy to hide the vast majority of the wiring from the loom connector inside the fairing, also it uses the existing fixings so no holes to drill.
2005-2009 are the same. 2010-on are different.