I'm not really sure if a tank less water heater takes more time for the hot water to get to the faucet than a regular tank style water heater. Perhaps a little longer because it has to heat water that may be at say 55 degrees coming from the cold water side instead of room temperature water that is siting in the pipes and then the hot water coming from the hot water heater pushes it out. I do think however (and this is a guess) that the problem can somewhat lie in people's mindset. Many people that I talk to about my tank less water heater think that I have instant hot water at any given faucet. A tank less water heater is not a point of use heater (unless it is directly connected to a faucet) but a water heater that is just not heating water when it is not being used. So yes you may have to wait a little longer to get hot water but you are saving a good amount of fuel by not heating water that is not being used. If you are concerned about wasting water you may want to look into a pump that recirculates the water when a faucet is turned on until it is the desired temperature and then it will come out of the faucet. I have not personally used one but have seen them on Ask This Old House I thing.