I've got great respect for the guys building their own heatpump systems, but didn't want you guys to miss out on this one.
Due to high subsidies on heat pumps in the Netherlands I was able to pick one of these up for just over a €100. The subsidy is €1150 and you're allowed to buy anywhere in the EU. This deal was so good I couldn't refuse it.
It takes about 4.5 hours to completely heat up the boiler and uses 250 Watts (COP is about 3.2). Filling up the entire boiler, according to the manual, should only take 0.99 KWh from 10 degrees C to 55 degrees C.
Using the touchscreen is easy and there are various programme options. I feel like the noise it produces is acceptable, however it is much louder than the on-demand gas heater.
Would I buy it for the full price or even half priced? Probably not, the savings of this unit are not going to be huge. However it has brought us very close to going full electric and dumping our natural gas grid connection.