Dave has gotten a lot of attention here since his involvement in the big japanese knife group buy (unfortunately I had to pass on it and am still regretting it). He has consistently been helpful and very nice in all of his posts. And all of the participants of the group buy who have posted about it have been extremely impressed with the edges Dave put on their knives. I have never personally seen his work but when I eventually buy some good quality Japanese knives they will definitely be going to him for sharpening.
I was part of that group buy. I can attest that Dave put a great edge my three knives, and would definitely use his services again. He even does some nice handle replacement work.
I bought a copy of his Japanese knife sharpening basics DVD set a week or two ago and can recommend it. The first DVD covered stone choices and the second was hands on sharpening. It gives a good foundation on both materials needed and some theory, the practice part is all on you though. It's no substitute for live instruction, but I liked it.
No I use them very often especially the Santoku, but they really do hold a great edge. They are made with extremely hard metal and Hattori knives are known for their sharpness. That is why in my opinion Japanese steel is far superior.
I agree that you don't want to experiment with the Hattori knives, but would encourage you to get Dave's video, recommended above, and try your hand at sharpening some western knives. Learn to read the bevel and practice holding a steady position as you hone.
I think that the skills learned this way are transferrable to Japanese knives, if you can read the bevel, you can hone asymmetrical knives as well as the western knives.
There is a great satisfaction in sharpening properly yourself, but Dave will do a great job if you choose to have it done. I participated in the group buy and my knives are the sharpest I've ever used.
Indeed, Dave is the man your looking for. He is the guru of Jap knife sharpening. Im confident to say he has done thousands of knives.
If i didnt personally have my own waterstones (incidently, some purchased from Dave), i would ship my knives from Aust. to him so he could weave his magic.
Any of the fellas from knifeforums.com would agree.