I only sharpened my Shun Classic VG10 knives once since I've owned them. It really depends on if you use them a lot. How often you use them and what you are cutting.
VG10 holds an edge quite well. In a pro kitchen cutting over 20LBS of produce per day will mean more frequent sharpening. I think you'd be best off of getting a basic combination stone and sharpening sparingly...If you feel the edge just isn't what it used to be then you will have to sharpen it a bit a longer then a simple touch up.
Just be sure to hold the blade at a steady angle...All this nonsense about 15 degrees this or 20 degrees that is pretty much BS...Nobody can precisely hold the knife at perfect angles. Free hand sharpening is a subjective art. If you insist on a more automated system the edge pro would probably be a good value.
I think Shun knives are very pretty and made just okay compared to other budget Japanese knives. I honestly feel like shun sharpens the knives at too steep of an angle to show of how sharp they can be. After awhile they seem a bit chippy. I've put more of a bevel on my Shun Classic 8 inch and it's been more durable and less chippy.
If you have to steel the knife frequently after cutting a single item such as a potato or tomato then it's probably time to re-establish the edge. Steels just keep the line straight then don't actually remove enough metal to make a new edge.
I would recommend you buy the basic cheapo combination stone from Mark. It will probably get the factory edge back in no time.
Only an abused knife will need to be re-worked extensively. I think Shun makes great knives in comparison to Global and Wustoff. They are clearly better in terms of edge retention and steel quality. But that is also subjective.
A few sweeping motions on the combination grit stone will probably give the knife enough toothy feel and cutting ability to feel like new again.
I think too many people insist on overly complicating the sharpening process. If you can feel the knife slicing effortlessly through tomatoes then enjoy it
If you insist on going crazy with micron grits and microscopic polishing...go right ahead. But chances are simply touching up the factory Shun edge will give you very happy results
I got my Shun sharp on grand dad's cheapo arkansas stone...It's all I had and I was tired of my dull knife. Of course I took lots of metal and dished the stone to smitherenes....But I got a new bevel and learned a thing or two.
Sometimes less is truly more with sharpening. Have fun...There is a great satisfaction of the DYI touch up sharpening. You'd be surprised to find that about 5 minutes of labor can give you a better edge than lots of so called pros. Lots of jerk o's in the industry just take knives to belts without any concern for metal removal and put a toothy fat burr of a bevel on knives and call it sharp. That ain't sharp and you shouldn't pay for it.
The 44$ combo stone will probably be all you need to touch up the factory shun edge. In the future you might want to consider getting a lower grit stone for repairing a broken tip.
If you don't intend to sharpen multiple knives year round a significant investment in stones does not have to be made. Self sharpening is a beautiful thing and I guarantee you'll want to cut all the produce in the house after you touch up the Shun.
As much as people despise Shun for being a mainstream overpriced product they are not that bad. But after using them I've learned that the Tojiro is pretty much a better knife at a fraction of the price.
I'd just get the cheap combo stone and then practice on rusty old carbon thrift store knives...if you can find em. Those forgecraft knives have all of the sudden became special. Heheheh carbon with patina oooh yeah!