I have been incredibly satisfied with the Yakima setup I got off CL to transport my kayak. The kayak is a 68 lb (hull only) Hobie Compass; I ended up scoring a Yakima Showboat 66 load-assist roller, and the Sweet Roll cradles - all used 1 time, for $200. The seller also threw in some older cradles which I haven't used. I mounted this to the factory rack.
Anyway, this setup makes loading the yak rather simple, and does a great job securing it.
Here it is, bare. The aft cradles have rollers built in, so that once i get the yak up there, positioning it is simple:
Two latches secure the Showboat, undo those for loading and unloading. The back part is a roller, so when the bow is on it, a simple lift of the stern and a wee bit o' ass gets it on the rack. Dismounting is a breeze, bring the stern to the ground, then walk the bow away from the vehicle.
Two included straps secure the kayak to the rack, and bow and stern lines for additional safety.
It takes me a few minutes to load and unload - most of the time is spent on straps. One thing I've found is if the loading process is easy, I'm much more likely to go more often. 10/10, fully recommend.
Now I need to find a way to keep my feet warm in the cold water...