回复: Writer's Workbench ~~~
Readability Analyzer combines some readability scores and lexical coverage statistics which, as you pointed out, can be collected with many concordancers, such as WordSmith and AntConc.
Writer's Workbench is not meant to be a research tool, but a writing aid, which features some good semantically classified word lists at the background, like general nouns, abstract nouns. I don't think the in-built word lists are exhaustive. As I said, the tool is not designed to be research oriented in the first place.
Nation's "Range" incorporates Michael West (1953)'s level lists (ca. 2000 word families) and Averil Coxhead's 570 academic word families.
You will have to make a decision on which lexical features you are going to look at, in search of stylistic features in your literary texts, and think before you apply any of the features to see whether they are good indicators for your purpose.