Personal tastes I suppose. I always liked the analogue trigger and joystick layout of both the DC and Xbox-S/360 gamepads. Niether was really designed with the D-Pad as the main focus, as most games use the analogue sticks and the D-Pad for option/menu selections in game.
I think for any games that require precise digital D-Pad control a proper joystick will always win over a D-Pad any day. Hence the reason I use real Amiga joysticks and an X-Arcade controller for emulation most of the time. Or my Slik-Stik Classic based MAME cabinet.