Others disagree, but I think you will regret tying the GPS to switched power. It will turn off every time you turn the bike off - gas stops, etc
Actually, my 660 and 665 ask me if I want them to stay on (battery power) or off every time I switch the key to off. Sometimes I do and sometimes I don't, so switched power isn't necessarily a bad thing.
Salty Fog Rally 2007, 2009, 2011, 2012, 2014 And DRAT! Missed the last one in 2015!