I finally tried the Deuce in June 2012 and I'm really torn on it. Can't beat the $7.00 all day if you're looking to save money, but the two trips we were on were standing room only (walls of humanity...not fun) and one had a unwashed homeless guy in a Duffman costume begging the whole trip. The ride from Stratosphere to Fremont was painful, it stopped so many times and kept adding more people to a very full bus. It got us there, but to be honest we just took a cab back to the strip at the end of the night even with a valid bus pass each.
My bottom line, if you're doing a ton of touring and/or trying to save money and don't mind being a sardine to save a buck...The Deuce may be for you. For me I think I'll stick to my shoes and cabs. But I do agree that it's mostly full of tourists.