Hi,
I've just held my wedding at Ban Heng @ Orchard Central 2 weeks ago. Probably too late for the original post now, but here's my experience for whoever comes after me:
= Venue =
Floor space - We had 25 tables set up, which filled up the space nicely (we had the entire restaurant to ourselves for the night). Ban Heng claims to be able to hold up to 30 tables in this place, but I think that will be a tight fit. Also take note that in order to fit 20+ tables, they need to open up the private dining rooms, which are separated from the main area for the most part by glass panel walls. Depending on your guests, it may look a little awkward. If you are looking at <20 tables, you can probably fit everyone in the main area (which also means they can continue catering to normal guests in the private dining rooms).
Stage / AV set-up - There are 2 possible locations for stage set-up, as well as 4 screens. We plugged in a laptop we brought into the AV set-up near the back of the restaurant, & the music played fine. Depending on your table layout, some tables may not have a good line of sight for the stage.
Venue decoration - Decent standard stuff.
Other layout details - There's a garden just outside the side entrance, which makes for a nice semi-private spot to hold your pre-banquet cocktail reception. There's also a tiny bride's room behind reception, if you need to change dresses or touch up during the banquet.
Solemnisation - There's no separate room for solemnisation. However, they can set up a table & chairs on the stage if you are willing to have the ceremony there. Ring pillow provided.
= Management / staff =
Friendly & professional. We kept changing the number of tables till the last minute, but they were prompt in helping us update the table layout after each change.
= Food =
Food is good. It's a restaurant, after all.