I haven't heard this performance, but the original 1972 Decca recording with the National Symphony Orchestra and the Westminster Symphonic Choir under Antal Dorati is one of my prized possessions. Talk of this performance being less than representative is silly, since the U.S. premiere under Dorati was (I believe) the 14th presentation of this work, and was done under the close supervision of Messiaen himself (as were they all then). I don't believe he would have stood for a less-than-representative performance of his work, particularly one recorded for posterity.
This work was received with wild enthusiasm at its first performance, and, I believe, at most of its subsequent performances. The first was at the Coliseu in Lisbon as part of the 1969 Gulbenkian Festival. According to Messiaen's diary (as reported by Peter Hill in his wonderful new book) the audience of 9000 (!) applauded for a solid half-hour at the end, and Messiaen was completely overwhelmed.
Anyway, I haven't heard the Chung performance, and I must say that I'm somewhat hesitant to buy it, for the following reasons. First, just based on the Music Sampler snatches here, I don't agree with many of his tempi. They seem to drag a fair bit, and Dorati's reading definitely has more gusto. Secondly (and please bear with me), if you listen specifically to the beginning of the 9th movement (Perfecte conscius illius perfectae generationis), you'll hear a big fat chord of resonance repeated several times followed by a very low note on the trombone (I think, I don't have the score), then that note is repeated with much more force by all the lowest instruments (I'm assuming double bases, saxhorn, contrabass tuba, and some low tam-tams), and this is followed by the baritone male voices one whole note higher. In the Chung version, these low notes are somewhat tame, and each is distinct to the extent that they sound like completely separate occurrences in sequence. In the Dorati version, the low trombone is followed by a shattering, rolling, rumbling paroxysm, and the male voices ride the gradual decay of this enormous sound. This part sounds for all the world like the creation of the universe. With sounds like this, you really start to understand what Messiaen meant by "explosions of blue-orange lava" and all the rest of it. By comparison, I think that the Chung version is much too civilized. Finally, concerning the criticism of this work's apparent lack of form or structure other than "blocks", all I can say is that repeated listening, particularly of the second "septenaire", reveals a definite sense of structure, sort of a gradual rise toward the shattering climax of the 13th movement, when the complete trinity appears on the mountaintop (Tota trinitas apparuit). The final chorale of movement 14 (Choral de la lumiere de gloire) is a completely fitting coda to the whole affair. Again, careful, concentrated listening to this part of the work will reveal amazing shades of harmonic complexity that are completely mindblowing. In most (if not all) of these chords, all 12 notes of the chromatic scale are sounding simultaneously, and it is only their judicious distribution across the various levels of pitch and timbre within the orchestra and choir which gives the impression of a tonic progression. However, if you try to hone in on a any specific group of notes to understand "intellectually" what the progression actually is, you lose it. It's a bit like what Aristotle said about time, that everyone knows what it is but nobody can say what it is. This piece, and by extension many of Messiaen's later pieces (from the late fifties onwards) represent (in my humble opinion) the absolute pinnacle of harmonic development in all of Western music.
In any case, one can't expect everyone to like it. As Messiaen himself said (again, quoted from Hill's book), his music is targeted to an initiated elite.