I tried saddle mounts early on, with boat upright, and with my blue Revo, I quickly had wear showing where grit/grime got between and began sanding the boat. ugh.
Now I use those small canoe gunwales mounts on my bars., and carry boat upside down. http://www.rei.com/product/849951/yakima-keelover-canoe-carrier
Bought the earlier versions cheap on ebay, work great, when positioned properly the boat is locked in.
Regarding load assist.... I have a tall 4runner. From the side of the truck, starting with boat parallel with truck, front of boat about even with front tire. I lift the front of the upside down boat, onto top of a towel over the front door and front bar. It now won't slide or move while pinned there, as I then move to the boat rear, lift and ease it forward, then over the 2nd rear bar. Then just slowly walk each end of the boat into the gunwale holders.
This youtube load is very similar, but without the extra bars/parts. And my boat is upside down. http://www.youtube.com/watch?v=IH5VyRuotLE
I used to load from rear using these same gunwale holders, but boat crashed off to side a few times before I reached them!
Side load is the way to go! No scratching, and never lift more than 1/2 the boat weight, all with good control.