L Kilkenny spoke well for me, in that I've used centerfire scopes on 22's for a bazillion years - shooting squirrels and whatever - and didn't know that they were supposedly worthless for that application. Heck, I even won a 100 yard rimfire shoot with my 39A and a 4 power Weaver. Must've been pure luck (probably it was weak competition, but I still have the trophy).
Years back, if you wanted to put a scope on a 22, you pretty much had to use a centerfire scope, or one of those 3/4 inch tube bits of junk.
As for the OP, I'd put the best scope on the centerfire rifle and I'd go get the Nikon 22-specific scope with the BDC for the 22. I like the idea of BDC on a 22LR for those 75 and 100 yard shots.