The Kono and the Ultimatum are two very different beasts. Both work equally well on the line with stuff like slicing cooked protein, but the Kono is a lot thinner. Not the the Ultimatum is an axe, but it does fall on the "mighty" side of the line. They're somewhat similar in general shape, both being fairly flat with some convexity. My particular Ultimatum is very close to a zero grind on one side with the other side having a very distinct "facet" on it.
My suspicion is that the M390 knife will hold a usable edge for at least four times longer than the Konosuke, maybe longer. This is just based on comparing how it wears vs any knife in White #2, White #1, Ao-ko etc that I've had a chance to use. But we'll see with time.
The only minor issue I have with the Kono is that while the spine is eased (a nice touch!) the top corner where the machi meets the spine is extremely sharp. If the blade was seated another mm into the handle it wouldn't be an issue but as is it sometimes "bites" my index finger when I'm using a pinch grip. Not a deal breaker, though. I may use a file or emory board to knock the point down a bit.