My problem with that kind of spout is the impossibility of adding fuel to any common car with it. Those dinky spouts and the angle they are mounted on the can make it impossible to use on a vertical gas cap cover going horizontally into a vehicle.
My answer to that problem:
Now you can argue with me 'til you are blue in the face, but this expensive safety can beats your little plastic can for several key points.
1. It is fireproof. Unless you put it in a big fire until it reaches a BLEVY temperature, this can won't add to a fire, and will burn off any exterior spilled gas and go out. Yours will melt and release all the gas within.
2. It doesn't form any condensation, despite being metal. The springs on the stoppers are so stiff, it holds atmospheric pressure. Side effect: on a hot day, it does burp rather prominently when you pull the pour lever.
It has no daily air exchange, and consequently no condensation.
3. It is a nice easy job to add fuel to any vehicle or small hand-held device. Trickling gas is just as easy as the can you prefer, and it probably pours out 5 gallons faster.
4. Unlike your plastic can, there are still safety features present when filling the can. There is an explosion-proof screen on the filler neck, and if something did cause a fire, jerking out the pump's nozzle instantly seals the can.
Yeah, they are damned expensive, though. My POS personal vehicle has a fuel gauge that won't work, despite all kinds of electronic wizardry having been attempted to fix it. So I just set the odometer each time I fill, and I remember when the last available mile is going to happen. That splendid safety can sits in the back of the SUV and doesn't stink up the vehicle with gas fumes, although it did get turned upside down once and the lever was pressed enough against other junk until it did leak a little fuel.
Perhaps the Jerry cans will survive the upside-down on the fuel spout treatment, but I know anything with a pushbutton on the top will be subject to opening if it is upside-down with the weight on the button.
Nope! You cannot see how much fuel is in this can, regardless of what you do. Picking it up and shaking it is the only way to evaluate the remaining fuel.
Plastic can wins on that point.