Personally, I prefer the Pro Controller d-pad to the Pokken d-pad (not to mention the wireless/wired difference). But I suppose that's a matter of taste. For reference, the Saturn S pad is my favorite controller/d-pad of all time, and my preferred fighting game input device even over good Sanwa sticks (actually used an official Sega USB Saturn pad as my weapon of choice the only time I competed in Evo in the PS3 days - even won a couple SSF4 matches!)
That being said, the diamond shaped button layout bugs me more than the Pro Controller OR Pokken d-pads for fighters that use 4+ buttons.
I play on my Pro Controller for non-fighting Neo Geo games or for some casual fighting game play. When I'm feeling more serious about fighting games, I prefer using a Madcatz TE2 and one of these:
http://www.brookaccessory.com/product/
You've got the best game in the series already. The rest are redundant.
I actually prefer the older games to WHP. WHP (and WH2J, for that matter) always felt a bit too fast and twitchy to me in comparison to the first two games.
WH1 is one of the more blatant SF2 clones out there, but it does have the bonkers Death Match mode (electrified bomb filled arenas? OK!). Plays well though.
WH2 (vanilla) is my favorite of the series, since it has the feel and SF2 clone characters of the original, but several new and fairly inspired character designs (Captain Kidd, Mudman, Erick, Ryoko, Johnny Maximum... these were some pretty good character designs, especially considering the time). Everyone has their own stage. An improved Death Match mode with tug-of-war lifebar and 10 count knockdowns.... It's my personal pick. Might have to give it some negative marks for the insanely cheap Dio boss fight, but it's not as if WH2J and WHP significantly back down from that style of boss design (hell, Zeus in WHP is arguably at least as bad, if not worse).
WH2J drops the Death Match, but has the weird team battle arcade mode format that is interesting to me, and was sort of picked up for Real Bout Fatal Fury. I kinda wish ADK had gone all in on the team battle idea, much like the KOF series or Capcom's "versus" games (though WH2J predates both). They were onto something there, but didn't commit to it enough - especially with it only being for 1P arcade mode for the first four rounds.
WHP removes all of the interesting death match and team aspects, just a straight up fighter with a couple extra characters, an unfortunately small number of backgrounds, and that pacing that I was just never super comfortable with.
Sad news. Gonna have to fire up Waku Waku 7 today in his honor.