I like it quite a lot as a great option in the chain-mecca that is Hunt Valley for lunch. I've also been for dinner. They are quite the "fusion"-y place -- there's Thai, Korean, Japanese, Chinese, and other Asian influenced cuisines on the menu, but they seem to do each one pretty well. They do have a yaki bop in a hot stone bowl and good sushi. I haven't tried many of the dinner entrees though my dining companions seem to have enjoyed them. The full menu is at www.umisake.com.
Looks like Elizabeth Large will have a review of Umi Sake in the Baltimore Sun this weekend (per her Dining @ Large blog).