Buy Criterion Collection Set and sell my Godzilla DVDs & Blu Rays?

Dr. Yamane,
The Classic Media DVDs have special features and commentary tracks that will not be ported to the Criterion release. I'd hang on to them, especially for the excellent commentary tracks.

The only thing the Kraken Releasing Blu-ray have are the movie trailers. I don't think the Criterion set will have those either.

The 2012 Criterion Godzilla Blu-ray will be the same exact one in the Criterion set. So you can get rid of it. Also the King Kong vs. Godzilla Blu-ray from Universal and Godzilla vs. MechaGodzilla DVD from Sony have no special features. Those can go too.

I do want to note, however, that the only movies that include dub versions on the Criterion set are Invasion of Astro-Monster, Son of Godzilla, Destroy All Monsters, Godzilla vs. Megalon, Godzilla vs. Mechagodzilla, and Terror of Mechagodzilla.

@G. H. (Gman)

That is very interesting. Also, for a Disney-esque "2-disc Special Edition" DVD of Godzilla 2014,  what would be the best to get for those "Special 2-disc Bonus Features"?

Personally I would keep it all. As Gman said they have stuff Criterion doesn't have. 

ET13 Productions,
I mean, yeah, I'm keeping all of mine. But for those who may want to get rid of a few, but keep those that have particular features, you lose nothing getting rid of Criterion's Godzilla, Universal's King Kong vs. Godzilla and Sony's Godzilla vs. MechaGodzilla.

MinecraftDinoKaiju,
As far as I know the standard Blu-ray edition for the 2014 movie has all the special features that are available for the movie. There was a Target Blu-ray exclusive that had some extra content back in 2014, but that's long gone.

As for DVDs, obviously the 2-disc Godzilla DVD set would have more than the one disc, which is probably just the bare bones movie. But even the 2-disc DVD set won't have as many features as the Blu-ray.

That's about as much as I can say on the subject. I don't do too much homework on the newer movies since they're so easy to find.

@ G.H. (Gman) Thank you for your insight and to everyone on this thread. This is super helpful. I'm a big fan of Ed Godziszewski and love his commentaries (especially on Godzilla Raids Again...his dry humor is great). Though I'm psyched he's doing the essays in the Criterion booklet I'm disappointed his commentaries will not make their way over to these Blu Rays. Very good point and I'm seriously considering hanging on to all the Classic Media DVDs. And I guess I didn't read the fine print: that leaves 7 films in the set without an English dub track. No great loss for me personally because getting to watch these movies in Japanese in recent years has been a real treat and brought new life to the films. And when you consider that some of those dubs are pretty bad (Godzilla vs. Gigan, Godzilla Raids Again) you're not missing much (though I love the subtle differences in the American versions of Godzilla vs. The Thing and Ghidorah).

I know that the American release of Terror of Mechagodzilla, removed a brief nudity scene from the movie. I guess the suits at Hollywood were allergic to boobies

Dr. Yamane,
Godziszewski is a great guy. I interviewed him a few years back and his book/commentaries have been insightful. I'm mostly hanging on to the Classic Media discs for references and to look back on the dubs for historical purposes.