My worst Vegas trip was with four other couples. Utter nitemare. Trying to get ten people anywhere at 6pm always means you are ready at 6:30. We had three cars, so who was going to drive was an issue. What to eat, where to eat, what show to see, ect, ect.
I'll take a solo trip anyday. I eat when I want, I sleep when I want, I see what I want, I lcan leave the seat up if I choose.