very nice document, thanks for the link! however, it tends to keep me siming for the homerun system. their take is that hot water is actually faster with HR, you disagree? another interesting thing is that the original owner had the water heater installed in the attic of all places, but being directly over the master shower it makes for a real quick hot water delivery time. PITA to replace though, i have done it twice, and each time have drained and left the old one up there. now that i have added a larger attic ladder i may take them out.
house is not large, 1850 sf. other than the amounts of tubing needed (cost not a factor) what makes it undesirable to you? do the maniblocs eventually fail? unused outlets leak? dont they offer caps?