Yes, I spend about 4 hours listen to different amps at the store in Tokyo before I decide to get the national. Mk II is indeed very black but when pair with my MH335DW, the bass is a bit too much for me. Same goes for the Mk III. Continental v2 and v3 are also nice but both of them hiss like crazy with my 335.
Very true, unfortunately I haven't heard the 335, so I can't comment. But I love it with both my Heir 4.A and 8.A. Very nice setup and pictures though!