Greetings! I am a student of philosophy at University of North Texas that digs a lot into scientific topics on my own. I personally own multiple physics textbooks (Feynman lectures, my university's choice textbook, Dover's Theoretical Physics textbook, etc) and this might be the best one for many reasons:
-It contains all the information contained in my other textbooks except for the content on electromagnetism (which is the subject of his second series of lectures on Yale's website) and quantum mechanics
-It is $25, the cheapest of all the textbooks I have seen
-It is small, lightweight, and only ~430 pages (The feynman lectures are multiple volumes, fragile, and bulky like the university textbook I have)
In terms of the presentation, it tops the dover textbooks (which are usually written like they are being presented to 1950's grad students... the equations are difficult to follow and there is little explanation of what is being done. The topics are kind of random and jumbled). It is on par with my university's textbook for presentation, but isnt a giant 10lb monster and has a lot less miscellaneous information that textbooks are notorious for (also, that textbook was almost $300... granted it contains electromagnetism topics as well). It is hard to compare it to the presentation of the Feynman lectures because of how... unique they are. I would say for a general understanding, the average reader interested in the mathematical physics and a more focused reading would probably prefer Shankar's book.
I think the best part is that there are just as many words as equations (with Shankar's humor that he adds in the lecture series that he based this book off of). This DOES require a little bit of pre-requisite mathematical knowledge, but nothing extremely complex (if you understand how to take a derivative and anti derivative and are familiar with the idea of sines and cosines... you will probably be fine. Otherwise, all you will probably need is to watch the lectures on Khan Academy's website for free and you will probably be prepared). This does go a TINY bit into partial differential equations (multivariable calculus) and deals a bit with extremely rudimentary vector geometry (linear algebra material)... but again, anyone with a basic understanding of high-school level algebra who is familiar with rudimentary calculus will be able to follow. Shankar explains everything that he thinks you might not know.
As a summary:
If you want to learn physics (not just the "facts" like in a Hawking book, but REAL mathematical physics) then this book just about trumps all. The only downside is that this is essentially volume one of what could be a three volume set (2 at least). I first started watching Open Yale Courses back in 2007 as a junior in high school and that has essentially shaped me into who I am today, and this comes directly from his first series there. He has since done a second series on electromagnetism, and I sincerely hope he also makes that into book just as accessible as this one.