I have been looking at tankless and have been considering.. but the difference in yearly operating was only $40...
the flow rate was very low as well to get that high efficiently rating. While a tankless may show a higher flow of 9-10gpm, it needs to burn hotter which burns more gas, so to be more efficient it flows slower. so no more than one shower at a time... plus, it only guarantees a 35* temp increase. which means in the winter time our shower may only get to 85-90*
and there are other drawbacks on both sides of the equation.
I have a maintenance closet which houses my Furnace and hot water heater, so any space savings is moot as I would not intend to store anything in the vacated space.
too many drawbacks right now... IMO to go tankless...