For anything requiring precision and a sharp knife, nothing I've used can touch a Japanese Wa handle.
For heavier tasks that need a duller, sturdier chef's knife, I prefer a plain old Western handle. The exact handle size and style is unimportant. Two factors that matter: a rounded spine on the knife (so you don't get blisters) and no bolster. Traditional bolsters are stupid. They making proper sharpening impossible. My heavy German knife, which I like in other respects, had a big dumb bolster. I had Dave Martell Grind it down to get it out of the way. If I were buying a heavy knife now, I'd get a Messermeister or any lower-priced Japanese yo-deba (western handled, heavy chef's knives made for abuse).
All these innovative handles look to me like they were created by marketing departments, or by inventors who don't really understand they're making one-trick ponies.
