In reply to Jonny S:
The way I see it wallnuts are the best single set of nuts out there. However if you are getting two sets (which most people want in the long run) I do think that one set of DMM offsets is the way to go they are the best nuts in flaring placements where other nuts often just don't work very well. Sideways wallnuts can work ok in these placements but overall they aren't as good and in thinner flaring cracks they are poor. Given that rocks better complement offsets than wallnuts do as they are more of a different shape I'd personally go for a second set of rocks in this case (offsets do have quite a lot of similarity to wallnuts they both have a groove in the middle and are quite wide nuts) .
So in summary if you think you'll only ever want one set of nuts (think winter climbing only, or easy routes like VDiff, or I guess short not that hard routes) then wallnuts are best, otherwise get offsets and the new rocks - I'd start with the new rocks in this case.
Post edited at 16:18