Thanks Tim for mentioning recped's videos. I looked those up and those were some impressive trips!
And thanks to recped for the photos. Those are nicely loaded canoes and I can see how the load would displace water. I have always ascribed to the use of air bags for use in whitewater, and will probably stick with my gear and bags in the canoe. My loads will not be as large as yours, nor my trips as long.
I just got some Harmony Bags today. It turns out that the 54" bag when inflated is only 48" long! At that rate of "length loss", I am going to have to put a 60" in the rear; I can then have, hopefully, at least 54" in inflated length. The 54" bag actually works well in the front with plenty of room in front of my knees for storage and bailing.