Heading to Vegas on March 17th... Booked Cosmo for the 17th and 18th, and then booked (Double booked on the 18th) for Aria, 18th, 19th and 20th, checking out the 21st. We have never actually stayed at Cosmo.. have used the room for my Daughter and our friends, but we have stayed at Aria our last 7 stays. I too upgraded for $30 a night. Aria beds have totally spoiled me.. but we we like Cosmo.. we will check into Aria and keep our stuff at Cosmo for the 2nd night.