Looks like a well built unit. Long warranty to match.
Replacing an conventional 40-gal hot water heater and hot water boiler. Not only had this saved bunch of floor space, but we hope to add years of peace of mind. The system is fed from a scale reduction, prefiltration system, so cleaning intervals should be fairly long.
Documentation is excellent.
We used Rinnai CH manifold system, as it greatly simplified and sped up install. Isolation valves system was also used on DHW side.