Adam C. Zern offers a few thoughts on Aristotle's Rhetoric:
"Reading Aristotle's Rhetoric was a good idea that ended up being far more painful that I would have liked. It is common for me to read the recommended or referenced books of intellectuals that I admire. Although I don't quite remember where I heard or read Rhetoric referenced, it did find it's way on my Amazon Wish List. I can now say I've read it, but I wouldn't say much more than that about it. (Word of warning: Rhetoric is extremely referential to Aristotle's other works, and I learned the hard way I should have provided myself a better foundation before jumping into this treatise).
The biggest problem with Rhetoric is that it's not all that much about rhetoric. At least, not in a way that a modern reader would expect. It doesn't provide a litany of do's and don't's for public speaking, something that a reader could get by reading Dale Carnegie's The Quick and Easy Way to Effective Speaking or the myriad of other self-help books on public speaking, but it provides surprisingly little information on rhetoric and the skills involved. The largest portion of the book is taken up exploring the varying traits and characteristics of a speaker's audience and why they are what they are. What makes someone noble? What makes someone a friend or an enemy? What are the idiosyncrasies of youth? Aristotle apparently felt that his interminable discussions on all things human would make his reader better at the use of rhetoric; I just felt it was unnecessary.
Like most things, it's not all bad. There are a few gems of true wisdom and some fascinating insights into rhetoric and the human experience, but it wasn't enough to sustain my interest. I made several notations and may use it in future writing, but Rhetoric won't be a treasured book on my Thousander list.
Read Rhetoric if you're like me and want to be able to say you have. (I'm on a quest to read as many 'foundational' books as I can). No doubt there are better books out there that relate to rhetoric and its uses and purposes. I enjoy the topic and will be on the look-out for other alternatives to Aristotle's Rhetoric."