In reply to sheelba:
I very easily find placements for HB/DMM offset nuts on gritstone.
I've never used WC offset nuts, but the DMM ones strike me as being more 'proper' offset nuts, with the WC ones being like Rocks with an offset twist to them.
Apparently a lot of placements are a little bit Rock shaped due to that being the most commonly used nut (perhaps more so in the past than now), which may affect your choice, but DMM offsets go in places where standard Rocks wouldn't be secure.
In the end it probably depend on how you think when you look at the rock, as to which nut works best for you, but DMM offset to seem like they're more thoroughly designed as offset nuts than the WC ones, to me at least.
On the other hand you might keep finding WC offsets to fit just right in the places where a normal rock doesn't give you a nice feeling.
I'd buy/use a couple of each for a bit and see which suit you best before spending big money...
Post edited at 14:34