A little introduction first, I'm a home cook and don't work in a pro environment so this review is from a home cooks perspective. Also this is my first Japanese knife (purchased from http://www.japanesechefsknife.com). I have a henckel's twin signature 8" chef knife (bought over 5yrs ago. It was almost free with Amazon points!).
I've had this knife for about 2 months. I did not cut any acidic foods with it for the first month. I developed a pantina with in a diluted phosphoric acid (yes, cola has it for free, but I diulted it down from 85% food grade phosphoric acid. It's amazing what you can buy on the internet) I then cleaned it with BKF (pantina was very non-uniform. guess, I should have cleaned it better... hind sight 20/20....) and a dark gray pantina remained. I just clean the knife with baking soda now (about twice a week or after heavy use).
Out of the box sharpness, well its the sharper than any knife I've ever owned (not saying much about my previous knives). I've since sharpened starting from 800 to 8000grit then stropped chromium III oxide (the green stuff), followed by iron II oxide (rust basically, red stuff), then I stropped on newspaper. I tested the sharpness by shaving my leg hairs..... I now have no hair on my right leg..... (I don't have much hair on my arm being Chinese, also I didn't want to take a chef knife to my face so leg hair it was!). I did the same with the heckels (no hair on my left leg...... I'm starting to question my sanity at this point.). Point being the two knives are as about as sharp as I can get them (I just started so take that with a grain of sodium chloride).
This weekend I cooked leeks and potato soup, Cantonese style braised brisket with daikon radish, and some collard greens.
3-4 lbs russet potatoes
1 (~3 lb) daikon radish
1 (bunch?) collard greens
2 stalks of leeks
some green onions
I diced the potatoes. Everything was great except for the times when the potato forms a vacuum seal on the knife face (very annoying) but the knife goes through very well with very little resistance felt.
For the collard greens I julienned the stalks and used the large leafs for chiffonade. Very pleasant experience here.
Leeks, I just sliced thinly. Similar to chiffonading the greens.
Daikon radish. I first quartered and then sliced into about quarter inch chunks. What I noticed was there was a some resistance near the tip of the knife. I think I need to do a better job sharpening there as I didn't feel this near the heel of the knife.
Cubing brisket. Not much to say here except that I wish I had more brisket to cut. I did get some blue pantina to form on the knife face though.
I'm really enjoying the knife so far. Could I have used the henckels? Sure I think I would have gotten similar results, but I just keep reaching for the Fujiwara instead. (Also the henckel's tends to get "wedged" in breaking down larger root veggies, which then requires me to use more force)
A couple of thoughts. Yes, the steel is very reactive you'll want to develop a nice pantina on the knife (why I used phosphoric acid). Also the steel is very stinky! I could smell the knife on my hands at first. I've cut up tomatoes and onions on it, I haven't found it staining or transferring taste to the food in my knife's current state so I when you have a panting on the knife you're good to go (just take care of it since it is carbon steel).