This book is simply the best treatment of the subject that can be found. Period. Having been written by Landau it comes with the guarantee that the material is presented in the most elegant, yet logically consistent manner possible. And this book delivers all of that and more. Similar to the approach in "Mechanics" the principle of least action plays a prominent role in all the theories: relativistic mechanics, electromagnetic theory and Einstein GR. As a result Landau develops the whole material through very plausible and very physical arguments, thus providing a very deep understanding for the material.
To put it simply, the derivation of Maxwell's equations are stunning. I have never seen a clearer, more convincing treatment. And as we have come to expect from this series, it is almost impossible to find any flaws(except for some typos which unfortunately still exist even in the most recent reprint.) The sections on radiation of electromagnetic waves and
The treatment of relativity is very consice and it is rather unfortunate that we could not get a more detailed exposition on the subject from Landau. It would have been extremely interesting to see what Landau would have had to say had he written this section after the "Golden Area for Black Holes Rsearch" As it is the discussion of Relativity from, as is to be expected, a principle of least action(Hilbert Action) is very cleverly done. Every section of the book is very physically motivated rather than purely geometric arguments. Reading this book gives you a fairly good intuitive understanding for the actual physics involved rather than simply an ability to write and solve field equations.
It might be a very good idea to read some sections of their Vol1. on Mechanics before attemting this book, with special attention to Chapters 1,2 and the last chapter on the Hamiltonian treatment.
But all in all, this is probably one of my favorite books both in terms of contect as well as sheer elegance of presentation. A geneuine masterpiece.