I have several Shun's, a couple of Kasumi's, and a few Mac knives for several years now.
I can say a few things:
-- All the Shun's are back in the cupboard. Once I discovered Mac, I stopped using them. They are bulky and lose their sharpening too quickly.
-- The Mac MTh-80 is the absolute Chef knife Its edge sharpness is beyond reproach, can be resharpened and stays sharp (easily passes the tomato test) for a month or two (I use Kasumi 8000 Grit whetstone for sharpening). I tossed all other Chef knives I had (Shun Santoku and French) once I got it. I also have a Mac Santoko, which I hardly use since the MTH-80 is more versatile.
-- I bought Kasumi short (3 Inch and 4 3/4 Inch) knives for jobs that a chef knife is too big for, and I am very happy with them. They are very convenient to handle, sharpen well and stay sharp (though a notch below the MAC).
--- I also bought later a Mac 3 Inch, since I thought this would be an upgrade to my Kasumi, but to my disappointment it was a downgrade. It is a different series than the MTH knife, the design is bulky and it does not cut as well as the Kasumi.
And while I am at it, there is another amazing knife from Mac -- the last bread knife you would ever need. Once you use it you don't understand how could you have cut bread without it.
Hope this helps.