I liked a lot of things about the book. I learned a lot from it, and it affected how I think about capital and inequality. I respect Piketty as an economist and realize that he is a brilliant, capable scholar who knows economics better than I do. His book is an incredible accomplishment and a major contribution to the economics and policy world. I focused my review on criticisms because, at the time I wrote it (in March), most of the reviews I'd seen were very positive. I figured people would get the positive stuff elsewhere; I did not anticipate the 10 million reviews that were to come, including plenty of critical ones.
In any case, my review boiled down to three critiques: (1) too much exogeneity, from interest rates to output; (2) no serious discussion of the optimal tax literature; and (3) not enough attention to context in terms of global inequality and actual poverty levels in the rich countries studied. It is likely that Piketty has considered these issues in other publications; I thought they deserved attention in the book. I don't consider my review to have been a "slam" on Piketty or his book; it's just a critique.
I don't think points (1)-(3) are terribly political. I think they are critiques that are likely to come up in any econ department seminar. I confess that I like mainstream economics and I like thinking with formal models. I have found that framework useful; I would be more convinced by the book if it were less dismissive of that framework. I don't have strong opinions about Piketty's policy recommendations; in fact, I lack a strong opinion about a lot of the issues that typically define American politics, and I suspect that my views on the few items I do care about don't fall consistently into one of the camps.
Wonks and others: stop trying to cram every economic argument into standard Left/Right boxes. Maybe it attracts more readers for your various projects, but it doesn't advance the discussion.