A few things further:
Reading the liner notes in my new box set that I received today, I realized that even the early records had stereo versions, although these were simply instruments on one side and vocals on the other, mostly for audiophiles. These stereo mixes are not false stereo, and the "echoing" was simply a strange artifact of the way it was recorded (all at once, with the vocal mics picking up the instruments and the instruments picking up the vocals and each other). They're still jarring, however. It is worth noting, though, that this only applies to the first two albums and the singles prior to "I Want To Hold Your Hand", which were recorded with two-track machines.
The only real problem I have with this set is the sloppy manufacturing. The printing has yellow and blue spots at random places, some text appears to have been printed multiple times on the same spot (there's a visible diagonal line in the Magical Mystery Tour liner book on one page, below which the text is thin and with small spots missing (still readable) and above which it's unintentionally bold and blurry-edged. My With The Beatles booklet has indentations on the very outer edges of the pages where it appears someone tried to staple between the sheets instead of in the middle. The contrast on all the pictures in all the booklets and on all the jackets is extremely high, so many pictures are very dark. The biggest problem with this that I noticed was that the cover of With The Beatles appears to be two light half faces on a sea of black. On my older WTB CD cover, their black turtleneck sweaters and the other halves of their faces are clearly visible. Strangely, pages 18 of the A Hard Day's Night came before page 17, causing confusion when I started reading in the middle of a paragraph. Lastly, the black box itself is damaged and WTB's CD has scrape marks on the outer edge, which I would guess will cause the documentary not to play right. I'm lucky it was where it was, since it's not on the music portion and the documentary is on the DVD disc, which is in good condition. I know this is a new box set because all the albums had the Apple stickers on the shrink wrap, so it must have been manufacturing problems.
Then of course there's the MMT disc, which claims to have the Let It Be documentary, as has been documented elsewhere on this forum.
Nevertheless, I'm still pleased with the audio, which is of course the important part and well worth the money if you can get it for around $100, which I did easily on Ebay.
EDIT: Turns out it's not just those two pages. The entire AHDN booklet is out of order, and in no predictable way. It's not even just that they stapled it together wrong. I don't understand.