My verdict on Beren and Lúthien: only get it if you're interested in new Alan Lee artwork, poetry, and a final example of just how big a chore it was for Chis Tolkien to edit his father's material. It is basically divided in thirds. The first part is primarily the original draft of the story, where Beren was an elf and it was Tevildo the Prince of Cats who captured Beren and from whom he was rescued by Luthien and Huan rather than Thû/Sauron. It's a comparatively rough draft, but close enough to what we wound up with and with enough altered names to be tedious.
The second part is old-school couplet poetry...I read somewhere that it is written in tetrameter, but since I haven't taken a literature class in decades I can't say that of myself. Reading poetry in the best of times for me is maddening (rhyme that doesn't end a phrase is annoying as hell) so while this is artistically the most important part of the book I will never read it again. Not only that, but it stops when the return to Doriath without the Silmaril. But that's a problem with everything here: none of the pre-existing material was ever in a final form or completed, so it had to be hodge-podged together.
The third part is, to borrow from Tolkien, flotsam and jetsam...pieces from various sources that didn't find their way into the Silmarillion narrative. Different accounts of how Beren obtained the Nauglamir and their attitudes toward it, and how it shaped the lives of their son Dior, his daughter Elwing, and her family, Eärendil, Elrond, and Elros.
Again, unless you love Alan Lee, ancient-sounding poetry, and textual criticism, stick with the Silmarillion version of events and forego the cost of the book.
