Finally I have completed the Kumisa III - right now I'm listening to it. A picture of the completed amp can be found here:http://ole.ine.co.th/kumisa/kumisa3_ole.j...
It looks a little messy, as I had to make some corrections on the PCB layout after it was already completed.
The ideas behind the Kumisa III design are compelling and very well worked out indeed, plus the designer is apparently a true music lover - something that is not easily said about some people who are into DIY electronics. The result is no less than Benny Jorgensen already described in his article. Using my HD580, my first impressions are very deep and perfectly controlled bass, absolutely authentic voices, superb soundstage and generally lots and lots of more details than I remember even from my favourite jazz recordings. The Kumisa III has a sound that simply "flows" - no better way to describe it. It's neither harsh/stiff nor smooth/soft, it doesn't make me think of transistors, opamps or tubes, just about the music I'm listening to.
I have built several amps in the past, tube, transistor and opamp based, but nothing really compares to this one. Sure, differences between amps are usually subtle, but in this case rather obvious.
I strongly recommend anyone who thinks about building an amp - go for this one! You won't regret it.