I am 6 foot even and for the last 20 years I always rode at least a 58-59 cm frame.
I tried a a friend's 56 cm frame and it was way too small for me to feel comfortable. I never tried a 60, but I probably will be comfortable on it as well, slamming the stem all the way down.
My sweet spot is a 59 cm frame, not many manufactures make frames in that size
Out of 4 bike that I currently have two are 58 cm and two are 59 cm.