And to begin with, I see it as an amazing addition and compliment to your other 3 APs. I like a variation in materials, sizes, and complications, and you definitely have that going.
I grabbed a few photos of this watch at SIHH 2013. It is very cool no doubt. It has just the right amount of grey and white colors with the dial markings, plots, and guard assembly. As you mention, nobody finishes ceramic as well as Audemars Piguet does.
Drawbacks? Well, ceramic is of course a brittle material, so a drop could potentially cause significant damage. I have never dropped a watch in my life, going back to age 6 or 7 when I started wearing watches. So I don't see this as an issue, but something to be aware of.
Another point to consider, the black dial black ceramic case 44mm Offshore has been replaced by this year's anthracite dial. So while this watch might still appear on AP's website (and for whatever reason the anthracite dial does not), I was told its production will be replaced with the anthracite dial watch. I have no information as to when, but if you really like this version, I would lock it up while it remains available.
Do keep us posted Ben. I imagine this watch with your other 3 and see a super well-rounded grouping.