I've been here about 3 times for their Korean style tapas and every time is delicious! Food is definitely unique and flavourful. I love their take on Korean fusion - definitely modern, but you can easily recognize the Korean influences.
My favourite dish is their marinated beef tartare. There are also a few other dishes that escape me right now. I've never really had a dish that I thought was bad.
The only issue I have with Anju is the pricing and the portion size. Things are very pricey given the size of the plate, and not really what I'd consider tapas. I felt that the portion sizes are not shareable, even amongst only two people. For a group of 4, we often had to order 2 to 3 of the same dish to make sure everyone was able to try some.
Service is always great and friendly. Drinks were also very good too. They also have some Korean alcohol, which is always fun to try (soju!). Overall good experience, but pricey!