Bests & Worsts Reviews from Amazon

I wanted to use this atleast a couple weeks before reviewing it. First off, I live alone, but in a 3 bathroom house. I have been keeping 50 gals of water hot in my basement for 25 yrs and finally decided to wake up. I installed this heater as a whole house heater in the basement where my old tank heater was. I was ready to deal with less than super hot showers, but I am amazed how well this works in both 1st floor bathrooms (1 tub, one shower), and even the 2nd floor bath(shower). Hotter water than I can tolerate in each one. BUT I DID LEARN THIS! I bought a 1.25 gpm shower head figuring I better cut back from my 2.5+ heads with this much smaller heater. WRONG! The first floor shower was hot and cold because i wasn't pulling enough hot water to keep the heater on. I then tried a 2.0 gpm in the downstairs shower. PERFECT. Consistent water as hot as I could want it (and I do not have the heater at full steam). Knowing the 2nd floor shower would have less pressure, I left the 2.5 gpm head on there, and again, perfect shower, no temp changing, hotter than I needed, and lasts forever if wanted. It still takes the same amount of time for hot water to get to my 2nd floor. I have always preferred a 5 min shower with a good shower head vs. a 10 min shower with a trickling shower head, so I do not think I am wasting any water. AGAIN, I am one person in this house, and have no problem NOT doing laundry, showering, and/or dishes at the same time. A couple or family could be perfectly fine with this heater if they could aviod doubling up on water usage. Not really that hard in my book, but your call. I also insulated ALL exposed pipes in my basement, under sinks, and some in the walls to help keep the heat in the pipes. Bottom line, so glad I did this, I think I will be saving tons of energy and $$$ not storing all of that hot water I am not using. I don't know why the manufacturers dont warn of using too low GPM shower heads, but if you think about it, a 1.25 gpm shower head is less than 1.25 gpm at 60 psi, and at 1/2 hot and 1/2 cold water, you are teatering at the heater on/off threashold. simple math.