Well, I can't say anything about the food, but I definitely had an interesting experience here. My mother and I were staying in Berlin over Christmas of 2012, and as being healthy eaters was proving to be difficult there, we were looking forward to trying Viakso. We walked in on a particularly cold, slushy night, and were excited to eat dinner. We hadn't eaten all day and were starving. Immediately upon entering the smiles left our faces, because when the server saw us walking in he started to laugh and shake his face. He walked over to us shaking his finger, very agitated, and said, "No, no, no, you cannot stay in my restaurant, you need to leave." We were shocked and exchanged confused looks. The server then said to us, "You are wearing fur," and pointed to our coats. We then laughed, relieved, and said, "Oh, no, these are fake fur! Its just really warm." Problem solved, right? Nope.
The coats were cheap, and did not look remotely real, but as it was about 20 degrees outside, they were very warm and cozy. Again, clearly not real fur. Well, after we told him they were fake, he at first refused to believe us, and then said that he "didn't care" if they were fake, and that just looking at it upset him anyway. He finally told us that we were "allowed" to stay and eat, but that we would have to "hide" our coats on the floor or outside, as it might "upset" his customers. Aside from that suggestion being ridiculous, we were the only customers in there at the time.
After we received this array of crazy reactions to our appearance (we hadn't said one word while he was talking, we were so shocked), I just started laughing and we walked out. He followed us out and called us names, as did a woman who we assumed worked there as well.
Starving, we ran away laughing at the whole ridiculous episode, took a cab back to the hotel, and ate gross rice cakes from the BioMarkt in our hotel room.
Again, the food may be amazing. I have no comment on the food itself, as we never even got to see a menu.