This is an 18" frame. I'm 5'11" ish and it is perfect for me although I own or have owned Konas from 17" to 20" and, due to their forgiving geometry, found them all fine.
It's currently got a pair of Conti' Sport Contacts on (really flying now!) and will soon be having my old Blackburn rear rack popped on for a bit of touring around Devon.
I did pay a pretty princely sum for this frame but apart from the Ritchey stem I had all the parts in the shed. Bargainous really!