My friends and I had a dinner their on Saturday. I was the only one who didn't have any sushi, but the others thought it was very good. They told us they have a star cook from Carlton who is great.
According to their web site (JIL - CLUB & DINING - SIEWERDTSTRASSE 71 . 8050 ZÜRICH . OERLIKON), all you can eat is 45 fr. but I have not clue what is included and what not. There is a menue there though too if that helps.