I wouldn't call it more efficient -- just different.
Also, your method might run into timing problem when trying to type the entire path along with the ~.
Typing ⌘⇧G prepares the popup for any path. So I don't have to worry about the path being in a KM variable.
More importantly, ⌘⇧G has long been muscle memory. No reason to change now. 
To each his own.