There is a tremedous amount of info on oil coolers in the Self Help Section.
My opinion:
1.) You are runng full synthetic (like Mobile 1 or something): you don't NEED one. Change your oil often and you will be fine. Find your own schedule for changing. For me in MD (~20F in winter and +90 in Summer) with a 100 mile daily commute, I change every 5K miles in the winter and every 3K in Summer (Temps above 70F).
2.) Oil coolers typically come with a valve (automatic or manual) that shunt the oil from the cooler when it is cold and then opens the circuit when it is hot. ~180F is the typical actuation temp. Other than that, I can't see any issues with flow or the restricting of circulation that is significant to worry about.
3.) Oil coolers typically get you (from the literature) about a 10-15 degree difference. Does that really matter? Here you will get the arguments about oil temp (in the pan) vs. temps at the heads and other areas. Oil coolers don't work unless you are moving, so traffic jams are still and issue.
4.) How much do you ride and for how long on a typical ride? 1/2 hour trips?
You are just getting to temp at that point, don't bother. 1+ hours: it could make a difference but if I am assuming correctly that Canada has probably 7 days above 85F a year, your Syn Oil keeps on lubing up to 300F before it starts to break, typical engine oil temp on a 75F day is ~230F at highway speeds AND HD's are made to run pretty hot (since there are not hundreds on the side of the road, melted every summer in the US) you don't really NEED an oil cooler.
5.) But, I think they look nice, so I will probably have one at some point
! The only thing I REALLY NEED is to ride... the rest....BIG WANTS! Toys are fune!!!!!!!!!:s