Interesting (to me) tidbit:  I was on a weeklong trip in Bowron Lakes back in the 80s with my 16' Wenonah WWC1 (fast but deep--sit and switch).  My partner was in an 18'6 solo kayak, which he had used on a 30 day solo kayak trip in Alaska.  A couple of days into the trip, he was frustrated that I had kept up with him.  So, for jollies, we did a sprint with loaded boats.  It was a tie.  I find comparisons between double and single blades amusing.  I'm an ex-WW kayaker, and ex-marathon canoeist, and own a fairly decent 16' touring kayak.  I paddle my kayak with a double blade, and my canoes with a single bent (or straight if there's whitewater).  If I had a pack canoe (not a PakCanoe, which is an elephant of a different color, and in which I spend most of my paddle time), I'd delight in using a double blade for which it was designed.