I prefer alloys, as I don't like spending hours cleaning & checking spokes. Alloys are fine for light rough but if you plan to do "stump jumping" & "quarry diving" go for spoked rims (as they can be beaten back to shape when bent). In my opinion the 12GS is a road machine that looks like an offroader !.
Go for alloys (and save money).
If you are going to get a gurlie yellow bike, get spokes....looks better IMHO.
If you are getting the boring Blue.....Alloys, and if you are getting the really cool red one, it has to be alloys. Sooooo cool.
I've been green laning, track stuff, ireland where the roads are shite, and France where the roads are good....and the alloys have been no touble at all.
I have wires and I DON'T spend HOURS cleaning them - and I keep a VERY clean bike - that gets ridden in the rain. Alloy wheels are easier to clean but not that much easier. (I have alloy wheels on another bike.)