It is great to see all these great tips on refueling!
I am still lifting my Wavian cans, so for the moment I am ok. With any sort of shoulder injury, that would be gone in a flash.
I have only had my Wavian diesel and gas cans for a little over a decade. They still look and act brand new. I replaced the o-rings ("D" rings?) on the gas can a year ago. Something in the fuel caused the originals to start cracking. The diesel cans are fine.
I love that they are leakproof. As in totally leak proof. I can fill up the Wavian tanks at the gas station and drive them home in the car over a very twisty, winding road, and not a whiff of fuel leakage. The same was never true of the plastic Jerry cans, even the no-spill cans, in part because there is 2000' of elevation gain, which tended to force fuel out of the plastic cans as the fuel sloshed around in the cans on corners. I routinely open the Wavian fuel cans a month or three later, and they are still under pressure from the altitude change. I no longer have any trouble with gasoline going bad. For me, those reasons make the Wavians worth every penny. I just used 5 gallons of pre-Covid gasoline with no issues. (I don't use much gasoline on the ranch, and storage is one of my issues.)
I have a couple of the No-Spill plastic cans still that I reserve for refueling things with small fuel tanks, like my gasoline generator, and for 2-cycle mix. I like them for small refills. The minor problem for me is that, here, I am always fighting temperature changes that swell and buckle the cans. I quit using the larger 5 gallon can as fueling anything with it was just too sloooow.
I used to have one of the US military style Jerry cans and then misplaced the spout. For years. After more than a couple of years, I gave it to a friend who had several, and about seven years later, I found the spout and gave it to him, too. Unlike
@oosik's mine had a cork seal, and it was less than leak free. Even the metal spout had a tendency to weep fuel. If it was a knock-off, it was an old knock-off. It came with the property.
Personally, I think that the Wavian design works better it a couple of ways; the three bar handle makes it easy to carry two empties in one hand, or one full can, and the cam-lock lids and spouts seal tightly without tools.
Yes, they are way more expensive, and I bought mine on sale for more than half off, but they solved a couple of issues for me (leaking fuel, and bad gasoline). For me using them is like using any well designed tool, a pleasure.
And no, I am not wild about the CARB compatible spill resistant nozzles. (But I do spill less with them.)
All the best,
Peter