We are on natural gas but have installed tankless in our last two homes. Both times we switched to tankless to make more room (tanked w/h were in laundry rooms and we wanted to put in shelves). In our previous home we installed it under the house and in our new house we installed it on the exterior wall. Water never gets cold even with several appliances running (dishwasher, shower, etc). Only be aware that you will have to wait for the hot water to reach your appliance depending on the distance between the tankless and the appliance (similar to a tanked w/h really). If given the choice I'll always go tankless! You also have no more worries that the tanked w/h might burst.

Forgot to mention we have hard water too. On the tankless you can run some vinegar through it once a year or so to remove deposits. Good luck!

When considering tankless you want to look carefully at the location of the unit. Try to centralize the location to the primary points of use. that is usually kitchen and master bath. When locating further from the kitchen I will pipe a 1/2" insulated pex line direct, and I mean shortest distance, to the kitchen from right off the hot outlet on the tankless. I just installed my new tankless and my longest hot water run is 16'.

Having hard water is an issue. Do you plan to treat the water? That is best. I'm having to look into it as well, but have made no decision yet on method.