I use Japanese Waterstones.
I think that's what I'd need to do on the Shuns. How hard is it to free-hand the angle? How important is it for the angle to be precise? Are there any guides that are worth using?
I have these like clamp-on angle guides for my hand files for tuning ski edges, I wonder if there's something similar for knives.
+1 on the waterstones, though good synthetics or arkansas stones are also good. I'm not a fan of the automatic grinder sharpeners. some are ok, but others shorten the life of a knife considerably and never approach the edge you'll get with stones.
Hand held is the way to go, imho. however, there are guides available and some are quite good. in either case, with the shuns (or other japanese knives) keep in mind that the angle is shallower (about 15 degrees) vs 20-25 degrees on western knives. once you get used to the proper angle, it's not too hard to maintain. keeping it as consistent as possible is best, but a little variation isn't too terrible. ditto on the need to use a steel to maintain the edge. if you do so, your knife will seem sharper and will need actual sharpening much less frequently.