I stayed in the Palazzo and went back and forth between Palazzo and Sands Convention Center. I believe Sands has a DAS as I got great B41 coverage most of the time. Except the meeting room I was in. I went back and forth between B25 and 3G in the meeting room however back to strong B41 coverage in the main halls.
I only got 3G coverage in Palazzo casino and Grand Canal Shoppes. I think Grand Canal has a DAS as I had strong 3G signal.