First off, this festival showed it was in its first year of operation. The first night the Ferris wheel wasn't operable and the trash cans seemingly got more and more full but no one was emptying them. Also, the walk to get into the festival could've been better thought out. You have to walk around the Hilton in order to make it to the check in lines which is far considering most people were getting off the monorail at SLS. We didn't experience the zip line or the Ferris wheel on day 2.
I LOVED the cashless system. There were really zero lines and everywhere we went we didn't have to wait more than 5 minutes considering the tens of thousands of people also at this festival. There were dudes walking around with mini keg backpacks serving you corona and negra modelo which was awesome because we had prime spots to view the performances from the main stage. The timing of the lineups was astounding you could walk from the Mercedes Benz stage to the main stage and still get a prime location for the next band.
It's Vegas and we were prepared for high costs so that's one piece of advice for anyone that don't be surprised when you get a 12 buck beer and 10 buck burger. But just soak in the guitars and have a good time. The ticket was already a high initial price, just assume the concessions and merch are as well.
We loved rock in rio and hope to be part of another one in the future.