We loved Bali Laguna! The atmosphere is really nice, especially outdoors in the evening by the little lake. Good place for couples. The food wasn't so good (we've had much better South East Asian food elsewhere), but the waiters were nice. Love the sarongs. This is definitely one of Shanghai's gems. Bit hard to find, though, so get clear directions.
So-so food (bit of a shame in a city like Shanghai), but yes it's nice pond-side. An inexpensive/un-glitzy night out for couples compared to other establishments frequented by expats - 400RMB easily feeds two.