common knowledge says that the "slit and cone" style wedge (shown on Cinelli) is not as good as the "angle cut" style (shown on the Ti) for a couple reasons: quill material must be somewhat elastic, yet resist cracking; round cone has more tendency to form a permanent bulge in thin steering columns.
I have used both styles with no problems of my own, but seen cracked and bulged examples of style #1...in either case USE GREASE.