I have a couple of the Agrisupply 10" burners. On my first trail run, it took 12gal of water from 64 deg F to 212 deg F in just over an hour (63mins). By the way, my regulator was not fully open (Oh, and my LP tank was nearly empty. It run out of gas a couple of minutes after boil). For my next runs I am planning to open up the regulator more, hope to get faster results.
This a great burner (and extremely cheap!!!). I think the Agrisupply burners are a great bargain at $30.
Hope this helps.