It may not come across as clearly in his writing, but in his talks Ajaan Thanissaro's comparisons of other methods and traditions are not denigrating and are extremely informative.
Here's his take on Zen's "Buddha Nature" for example:
"The idea of innate natures slipped into the Buddhist tradition in later centuries, when the principle of freedom was forgotten. Past bad kamma was seen as so totally deterministic that there seemed no way around it unless you assumed either an innate Buddha in the mind that could overpower it, or an external Buddha who would save you from it. But when you understand the principle of freedom — that past kamma doesn't totally shape the present, and that present kamma can always be free to choose the skillful alternative — you realize that the idea of innate natures is unnecessary: excess baggage on the path."http://www.accesstoinsight.org/lib/auth ... ature.html