All they are offering is a power vented water heater. Many other manufatrus offer this as well.
Want something a bit more commercial check out this Lochinvar unit. It uses a heat exchanger and a storage tank with a recirc pump, the smaller unit can handle 155GPH at a 100° F rise. Lochinvar Efficiency Pac
No A.O Smith makes a unit that has 96 % thermal efficiency. Called the Vertex GDHE-50 its very impresive.
These models can be easly found in the Chicago area. I hope this information helps a little.