5th scale -vs- Other R/C's

I'm looking forward to buying a 5th scale.See'n one of my buddies 5th scale buggy, I wanted to know if they can go about the same speed as some of the 10th/8 th scale ones ? I never knew that a 5th scale buggy could do a wheelie. A lot of people say that the bigger R/C's go slower, but when I see them they look like they go at least 50mph? Can any body give me some info If they know any? I wanna know some of the names of these top 5th scale r/c's that can reach the speed of at least 50-60 mph..