I bought this to load my 17' Grumman aluminum canoe onto my pickup. I've had Yakima round bars on the truck for all of its 20 year life, along with bike racks and ski racks, and I've carried the canoe on it many times. But it has always required 2 people to load it, except the one time I'd tried loading it myself and damaged the hood of the truck. At the canoe's weight of almost 80 lbs, it's not easy, and as I've grown older, my upper body strength isn't what it once was.
I've ranked this with 4 stars, because the instructions make it look easier to load than it is. Yes, it's much easier to load than without it, but it's still not easy. Perhaps with a lighter boat, or one that is carried upright such as a kayak, it would be. With a canoe which is carried upside down, it means lifting it upright onto the loader, then turning it over while still on the loader, then shifting it in steps onto the bars. I have not found a successful way of turning the canoe over first and then putting it onto the loader already upside down. Perhaps if I were stronger, I could.
Unloading is fairly easy by comparison, as one end of the canoe is resting on the ground while upside down, the canoe can be lifted off the loader and turned over in the process of lowering the other end to the ground.
As for the installation of the loader, it's fairly straightforward and is covered well by the instructions. If I could rate that separately, it would be with 5 stars. Any bar that has been in place for awhile will have some corrosion inside, which needs to be cleaned out first. Any straight rod or wire with an oily rag on it can be used, and that works pretty well. Once it's pretty clean, then lubing the loader tube and parts well will make a big difference in long term ease of use. I used some lithium grease that I already had, for garage door hardware.
All in all, I'm satisfied with the loader. It does what it's supposed to do, and it is elegant in its simplicity.