Sounds awful lot like a commercial for the company in question..
Personally, I looked at the idea of a tankless water heater.. Until a did some homework.. They simply do not "save" energy, in fact to get enough heat into the water they use a considerably LARGER, HIGHER BTU BURNER.
Temp control is a major complaint, they only can heat the water so far above the incoming water temp and water flow will change the amount DRASTICALLY.
Requires a MINIMUM WATER FLOW which typically is .5-1.5 gallons per minute just to turn on the burner.. This means you will use a lot of water in the process.
Something else you forget to mention in your commercial is tankless water heaters PLUG UP from mineral build up.. That means if you are not on city water (which is highly filtered and softened) you WILL be spending a lot of time CLEANING the tankless heater pipes..
So far, I have no problems getting a 15 minute shower without the need to turn the water on/off with a 6 gallon conventional water heater. Could even take that to 20 minutes if I wanted to..
The "trick", set the water so the shower head gives off a nice "pattern".. When done right you are mixing a lot of cold water with a little hot water (RV water heaters tend to output very high water temps, on the order of 130-135 degree) which allows you to use 1 gallon of hot for 2 or 3 gallons of cold. The result is a 10-15 minute shower if you use no more than 1 gallon of water per minute.