We used RTC as our transport around the downtown/Strip area and to the airport. The drivers were extremely helpful, except for one. Got us pretty much everywhere we needed to go, at least within a mile of our destinations outside of the downtown area. We stayed at the Golden Nugget and the bus stopped right outside. It was great. At the end of our trip, we got lost on our way to the airport and a driver picked us up and took us to the next connecting stop which wasn't even on his route and wouldn't even take a tip! Awesome! Will use again and again.
Don't waste your money on cabs. 1.2 miles was $13 not including tip. They charge distance AND time and will usually drive around for a bit, I know because I had my GPS navigation on and it was telling me of shorter routes with no traffic.