192 in the first test, a century in each of the last series, considering no one else has scored a ton in those games for NZ, I'd say he's carrying his weight TH.
If 30's in between are failures, I'd take that and say thank you very much. Most international batsmen on NZ wickets would.
I'm not questioning his batting form. It is good. Acceptable. Above average. I think it's our biased commentators that are really getting to me.