don't get me wrong it's not horrible and i made a lot of pretty good beers in there. my issue was i would lose around 5 degrees or so in an hour mash sometimes i'd lose more. there's just a lot of headspace in there and that seemed to let the temperature drift. when i did mashes that almost maxed it out the temp held great but if i did a normal sized beer that's when it'd drop. honesty if you make sure to preheat the mashtun before you mash in and maybe toss a blanket over it if you notice a temp loss you should be alright.