I like the round safety cans except they spill more when you pour. In south Florida the safety cans don't vent fumes like the plastic ones do. I have owned cars with semi-functioning fuel gauges or kept extra fuel in the back for portable generators or long trips upstate. I won't put the cheap plastic cans in my vehicle anymore. The fumes may me ill.
The safety cans are expensive, though. $40 and up for a 5 gallon with a spring loaded lid. The army/navy surplus store here has jerry cans with a screw-on spout and a vent hole that makes dispensing eisier. And yeah, they rust if you leave them out, so I keep them dry. Gas keeps longer in a steel can with a sealed top, too. No condensation inside in humid weather.