We did lunch at BOG two years in a row and pre-ordering saved a pretty good chunk of time - I would say at leas 15-20 minutes for us. When we didn't pre-order we were sent in the building to the right where we had to wait in a line and then were eventually told which kiosk to go order from. Of course our luck, the people at the kiosk in front of us couldn't figure out what they were doing and a CM had to come over and help them before we were able to order. The next year, we pre-ordered. We were sent in the building straight ahead to a cash stand where our band was scanned, our order confirmed and we were at a table within 5 minutes of entering the building.
We won't ever not pre-order again.