I ended up spending more $ and time building a 10 gallon mash tun from a cooler than I wanted to. So I returned everything and bought an 8 gallon mash tun from my LHBS.
It's basically just a brewcraft bucket with a false bottom and spigot etc.
They say they use it all the time when they brew at the store (though they use keggles personally) and it works great. Doesn't really lose much heat.
So anyone ever use one? Think it will retain heat okay?