I pre-ordered the bust, but soon after canceled it. I'm pretty darn happy with my PF Grievous and I think it would be a bit of overkill to have the 1:1 head next to the already imposition of space the 1:4 takes up next to it.
That's kinda understandable... The PF DOES take up a LOT of space!!!! But I'm trying to have a setup where I have the PF with the 1:1 bust (Vader, Maul, Greivous)