We bought gas geyser with the aim of saving money from the high bills of electric. When you open the hot water, and try to mix with cold water it suddenly gets more colder. You cannot open both hot and cold water at the same time.
Unlike most controllers, you can vary not just the startup pressure (which is what most other units do), but also the ongoing, running pressure output.
The controller is also much smarter than most of the slightly cheaper ones- it doesn't just give up for 24 hours if it gets no flow,for example, as some others do. For an extra 10% or 20% on the price, it's well worth the money to get a
much smarter product, that's clearly had a lot of thought go into the software.
The instructions, translated from Italian, are not the clearest, though.