In my youth, it was a matter of machismo to be able to dead lift and throw boats, even K2s onto the top of a vehicle. Those days are long gone. Plus, if anything goes wrong, besides hurting yourself, you can ding your vehicle.
I stupidly resisted getting a lift assist device until I had turned 70. I most often had my wife or a friend around to help lift: or alternatively, some stranger would take pity on the old feller who was obviously having difficulty lifting his boat. My wife was also getting quite perturbed that we were still lifting boats onto cars late in our retirement years.
Now we have a
Yakima ShowBoat 66 roller loader for summer use. I use a garden kneeling pad under the stern of the kayak and then just lift the bow onto the roller and push the boat up from the rear, easypeasy. It works very well and I am still loading kayaks and paddling well into my 70's, even with arthritic shoulders. Been a long time since I did a dead lift even of a 42 lb. carbon fibre boat.
For winter and early season use, when the XC ski box is on the SUV, my wife found a used
SeaWing™ Kayak Carrier with Stinger outfit that goes on beside the ski box. Same deal, pad under the stern, then lift the bow onto the stinger and push the boat up onto the cradles. I really like the Malone cradles as well.
I have some lady friends who have a hullavator for their truck and it works great. But it's way more expensive to buy, more complicated mechanically, and more complicated to install or remove. They have also had minor mechanical problems with it occasionally. Still, well worth the price for their needs.
Whatever the choice, getting a load assist device is well worth the cost. It takes "much less effort" and there is much less chance of injury, or vehicle dings. This is particularly true for older and smaller paddlers. Both the Sea Wing and the Yakima roller, are less than half the price of a good carbon fibre paddle so there are several price points and options for lift assist kayak loaders out there.
My two bits (loaders) worth. Cheers,
Rick