How do these compare to the 7 gallon aquatinaers sold at sporting stores for $8 ($11 @ Walmart's "low" prices). I have a couple of the aquatainers and they seel a little thin, got a hole in the top of one of mine and the plasitc valves broke on both. I do like though that they use a standard pipe thread in their caps so I screw in a 1/4 turn petcock designed for water heater drains so I have hose hookup.