This 40th anniversary series continues to impress. The 2010 stereo mix and the 5.1 mixes of Poseidon are excellent. The swirling mix of romance, hard metal and jazz make this sound as fresh and as relevant today as when first released in vinyl. The album's dynamics are similar to In the Court, but there's no sitting on laurels here. All tracks apart from the Devil's Triangle sound stunning. The latter never really worked for me, being a meditation on the theme of Holst's Mars, and the missing master tapes which limit its restoration is no loss to me; I'm sure others will disagree. Everything else is excellent, including the extras. It's interesting to get the many incarnations of KIng Crimson released out of sequence. Compare the tightly focussed playing on Pictures of a City on this album to the slack run-through in the extras included in the Islands release.
While this is not the best of the 1970s Crimson albums the first two thirds make it essential listening. If you love Crimson you'll probably have this release already.