Remember, when we 1st heard this it was on very inferior equipment, and recorded on sub-par recording equipment, most likely in mono? I think your not considering those factors in the decision. For me, I thought it was pretty good overall. With DTS master I guess you expect "more", but it is what it is- a 50 year old recording.
I first saw the film at the cinema back in 1964 when it came out. I cannot remember whether the main songs were different versions to those on the LP. However, looking at John playing harmonica on I Should Have Known Better it appears to match the version appearing on the stereo LP. And, although I know that there are those that do not approve of the sound of the stereo LP, I find it very much to my liking. If, as I think, the multi-tracks are still in existence, I feel a surround mix could and should have been made with a 1964 type of sound balance and not that which to me has a similar character to the recent Mark Linett remixes of many Beach Boys tracks. There were plenty of excellent recordings made back in 1964 and before. AHDN is one of them.
Each to their own. It is not often that I slam anything.