well, I got the shock in yesterday, got it mounted up, and took the bike out for a spin.... what a difference, the bike feels much more planted and the S4 forks work quite well with the ST2 shock, it feels like a different bike, the handling is greatly improved.
just want to add a pic of the bike with the shock installed... btw, mods so far include:
S4 forks
ST2 shock
SIL Titanium Exhaust
FatDuc
mods to come:
320 mm rotors and 4-pot calipers
748 Master Cylinder
Flyscreen