I can vouch for Dave's skills having seen him work first hand during my training with him. He has a great setup and offers a variety of different levels of sharpness based on your needs.
I have used Dave, (Jon...though only on an initial sharpening of a new purchase) and Mr. Sugai. I would not hesitate to use any of them. If you're fond of single bevels, Sugai-san does a very nice Uraoshi.