We went tankless 3 yrs ago when we moved and started a remodel. We put in 3. One in each bathroom, 1 in kitchen/shared with laundry. We love them. Only thing better would be solar. We broke them apart so we could have smaller units and the ability to run one off of a generator if needed. Plus all of our runs are short so no wait for heated water. If you are looking for a unit look for a brand name like Rinnai, Bosch etc. stay from unknowns.
If you are thinking of Water Heaters there is only one I would recommend, that is MARATHON! These are top of the line. High price but worth it. If iI ever go back to tanks this is what I would install