Yeah Zipang is really a rebranded Solomon no Kagi isn't it? I can imagine it being horrible to play with a d-pad that easily hits diagonals.
Hori Fighting Commander PC is a good 6-button controller with a cross-shaped d-pad.
Yeah it's like Solomon's Key but with different levels.
The D-pad definately looks more promising, i'll get one and see how it goes.
Your complaints don't sound like they are due to a mechanical error with the controller membranes, but rather a complaint about the functional design of the Duo/Turbo/PCE D-Pad. What is your opinion of the Master System pad, or Genesis/Mega Drive pad? I've always felt like my Turbo controller fell nicely between those two in terms of functionality. While not as glorious as the Genesis/Mega Drive controller, it was not nearly as bad as the master system DPad.
If you have an issue with the circular nature of the Duo/Turbo/PCE pad, I would certainly suggest trying the Hori fighting commander 6 pad. I picked one up not too long ago, and it responds almost identically like my SNES pads.
That being said, I really do feel like using a the Hori Fighting Commander pad contributes to the loss of the authenticity and nostalgia "feel" factor I associate with playing these old game systems. Like using a Genesis/Mega Drive controller to play 2600 Missile Command instead of using the Atari joystick - or in arcade with a track ball - the feel of the controller is a large part of my enjoyment of a system. Might as well play it on a keyboard with an emulator, if feel and authenticity is not a factor lol