Firstly, I can't for the life of me think what you mean by NGCMW
As for Spector's Wall Of Sound, well, it works in parts, but not others. The orchestra comes in too quickly on TLAWR. Across The Universe, I prefer the Spector version, actually. I heard the GM version first, and wasn't overly enamoured by it, then a few years later, heard the PS version and it became one of my fave Beatles songs. As for Let It Be, that song is fantastic no matter which version you have - I think I prefer the PS version slightly, but there's nothing in it.
About Paul & Ringo both playing drums on the song, I saw it in a little book that details all of The Beatles' songs in a short paragraph each. It slagged PS off, and said the GM version made "much more conservative choices" and the like . . .
The difference between genius and insanity is merely the difference between success and failure.