I enjoyed my visit to Belgo very much. I went for a birthday party, so we had the back of the top level to ourselves. The layout is a little inconvenient (a U shape with a big hole in the middle that looks down onto the lower level of the restaurant) but it ended up being a pretty good location for eating, mingling & (later) dancing.
The server was very nice, although a little inconsistent - she refilled my drinks & water constantly but completely ignored my tablemates unless I drew her attention to them. We laughed and worked around it.
I only had a French Onion Soup, so I can't say too much about the food, but that which I did have was excellent. Others at the table had lobster tail (fairly good), a clubhouse sandwich (sandwich excellent, fries left much to be desired) and a banana split (very good). Good value for the price.
I was shocked at how quiet it was on a Saturday night - not sure if that has to do with Calgary's downtown scene or the venue itself. Either way, I'll make another visit to try out more of the menu.