Yeah, this is one of the things that's *really* hard to explain to people using standalone PICs in the U.S., especially when they're trying to compare power settings with those on full-size induction hobs. I once got into a long back-and-forth with someone about how I had to use a power setting of 6-7 on my Neff to cook (American-style) pancakes properly, and he insisted that any setting above a 4/10 on his PIC would produce the equivalent of "cajun-style" pancakes, i.e., blackened beyond recognition. He couldn't believe a setting of 6-7 on mine wouldn't do the same.Just to pick up on this point: my Bosch definitely isn't linear. It has 1-9 and boost. You'd expect 9 to be 90% power, 8 to be 80%...
Testing both with a power meter and by timing water heating up, 9 is about 60% of boost. 7 is about 25%. Everything below that is just fine gradations. It actually makes sense; it allows fine control of a simmer, whereas when I want boost I just want all the power. But it took me a while to get used to it!
Oh, and then there's the issue of steady power output vs oscillating power output. Most of the PICs cycle on/off from full power to no power based on the chosen power setting. Meanwhile, most full-size cooktops just reduce power output and keep it linear, kind of like Panasonic microwaves with inverters.