Worth a blast on a bike? How long should it take, allowing for a little sightseeing en route?
We did avimore to the sea in a day and a half. Nothing terribly exciting about it but very pleasant.
Thinking about it we did Ben Aigan trails as well so that would have been a few hours extra
Edit - we didn't follow the routemarked speysie way the whole way - as we had full laggage we avoided the single track bits in one or two places and made up one or two bits of our own. I could do you a memory map of the route we ttok - we also carried on to inverness to get the train back south,
I would use it to visit ditilleries if i were you. Have been meaning to go they other way from the coast to tomintoul and then to aviemore but not got round to it yet.