I like them both. I like the Aria corner suite the best out of the 2 properties. The regular room at Aria isn't nothing to brag about and its not very open. The regular Vdara room may be a little better. But I like the corner rooms at Aria better than the corner rooms at Vdara.
Vdara is only like a 3 minute walk from Aria anyway so it's no big deal. I like to have too much fun often so getting to my room at Aria is usually a little easier and faster to go passout at 4am. Except the hallways at Aria can get confusing lol.
Vdara is usually cheaper and just use one of their promotion codes and get a bargain.