I switched from a induction cook top and extract / BIAB kits so I can't compare it to a full propane setup. I have assisted on a few brews with my neighbor on his three vessel system and I was very impressed with how fast he could get to a boil and how vigorous it was. He boils off over a gallon in an hour and I was only seeing 1/4 gallon boil off in the same time.
One reason I chose the Foundry was that it can be switched over to 240V when I'm ready. If you are used to propane burners I would highly recommend running it on 240V. It takes a good hour to go from mash to boil with 110V.
The Foundry is working great for me. I have brewed two 5 gallon all grain batches and had only one stuck sparge on the first batch. I slowed down the pump flow and added rice hulls to the second batch and that seemed to fix the issues. Overall I am very happy with it. The pump and the grain basket are huge upgrades from my other system. The delay timer is also a great feature.