I agree with Dan. I have both, but would not have paid full price for the upgrade – it was discounted when it was introduced.
I have WBC-NT. A technical OT commentary isn't much help to me now because don't know any Hebrew yet, so I didn't buy the whole thing. I do like and use the NT volumes.
I will admit to frustration in the sets that aren't complete at this time. Not Accordance's fault, since the 'missing' volumes haven't been published. But it seems that a lot of the sets I own are missing Luke, Acts or 1 Corinthians! Oh, well, I've got more than enough to keep me busy for a lifetime.