I have one of the VO posts, as well as a Kalloy like yours. I'd guess that the VO post gives about 1-1.5 cm more setback, effectively. The VO post is beautiful and very well made. I love two-bolt posts for their much more sensitive tilt adjustment, and this one is easy to install a saddle thanks to the "swing away" rear bolt. The VO post is MUCH easier to adjust for tilt than the Kalloy. Too bad it is only available in 27.2mm diameter.