I don't have the EnviroFlo, but ones just like it. Basically, the body is exactly the same, but the spout is different. I hate them, but it they aren't the worst. I have another can that I think is officially the worst ever, due to the spout system. On that can, the spout won't open until is it inserted into a fuel filler valve or the provided funnel, and the vent is so bad that it takes forever to empty the can, and the spout doens't seal, so fuel dribbles out as I'm emptying... I've only used it once or twice and gave up.
Anyway, back to these cans: I have 4, and I use them for my "strategic fuel reserve". I keep them in my shed out back away from the house. I did store one inside my car, once, and it leaked and ruined our trip from the smell... so I don't do that anymore. To-from the gas station and my shed, or in my trailer. That's it.