I have two propane powered ones. One for the house and one in an apartment. The initial costs are more but never running out of hot water is a major plus and you will save in the long run because they have no pilot light. Also, they have electronic ignition so no electricity, no hot water. If you can call it a con it would be that they need cleaning out every year by running vinegar water thru them to clean out mineral deposits. Make sure your installer installs the necessary valves to do that.