I'm thinking about installing one under my main kitchen sink as I'd really like hot water on demand there. Does anyone have any experience with these? How's the maintenance on them? I've been warned by a friend that these have a tendency to leak.

Back story: I just had a Takagi tankless installed when my old water heater died. I wanted to conserve gas, a precious commodity, but not squander equally scarce water in the process, and it takes about 3 gallons of cold water passing through the pipes before the hot water arrives at this particular outlet, which is at the furthest point from the Takagi. The second choice of course would be a circulating pump, but I'm not wild about first having to turn on a switch and then having to listen to the sound of a pump kick in before turning on the hot water faucet. This would be especially undesirable first thing in the morning, when you want things as automatic as possible.

Thanks in advance for any feedback.