With so many (deserved) critical accolades heaped on this franchise the question is not 'is this set any good?' it's 'is it worth it?' The answer is, unequivocally, YES. I could rave about the new transfer along with everyone else (it's great) but, in practical terms, the films look much better. Upconverting was never a friend to the DVD releases, seeming to bring out the flaws as much as the detail. The Blu-Rays resolve that problem and (for the most part) make these films look like the visual masterpieces they were in the theatre.
All of the 'Appendices' of the DVD release are here, along with the Costa Botes 'Making of'' documentaries that were previously only available in the limited edition DVD sets. Grittier than the other extras, these feature-length documentaries offer a different perspective on the films and are a nice treat for the LotR fan who thinks they've seen everything.
Masterful as this set is, there are a few things people may quibble over. The films are each spread over two Blu-Rays, a necessary concession for the quality of the transfer but some people might find it annoying. The features are all presented in SD, though I personally don't think remastering them would've added much value. Finally, there's the infamous 'green tint' some people note on Fellowship; I can't see it, even when I look for it, but some people might feel differently.
Rumours persist about some mythical 'Extended-Extended Edition' of the films, containing even more deleted scenes and extras that have never seen the light of day. Personally, I call shenanigans on such talk but, even if you believe it, such a boxed won't see the light of day until well after The Hobbit Extended Editions have been released (2015 or later). Given that fact, there's no reason for a Lord of the Rings fan not to pick this set up.