The film ran over 200 minutes, but was edited down to 81 without John Lennon's knowledge - with much of Lennon's footage cut.
The decision was made to blow it up to 35mm and exhibit it theatrically. As a result, a horribly awkward cropping resulted, which only got worse when it arrived on a VHS pan-and-scan version in the early 80's.
Around the time of the Beatles' Anthology series, Let It Be was re-mastered from the 16mm negative with the intention of re-releasing it, but plans were scrapped for unknown reasons. This re-mastered footage was glimpsed in the series, making the "available" film almost unwatchable by the standard that was set. Reportedly, the series also showed some of the cut footage.
Basically, the film was released in 1981 on a Magnetic Video LD, which was sourced from the 16mm original, but again, was cropped, panned-and-scanned. This was in addition to the VHS and Betamax versions, but a CED format was attempted, and failed due to low quality and bad performance of CED players.
As of 1997, a British company called VCI had the rights to release 'Let It Be' and they claimed they had the 1992 re-mastered footage. This is not to be confused with MPI who released Help and Magical Mystery Tour. MMT has been issued on Laserdisc a couple of times since 1992, and finally on DVD which is rare but still available. As it stands, this version is unfortunately the best available. Yes, it's washed out and could stand an overhaul, but it is what it is...
As to your original question, the version of 'Let It Be' that you have is about as good as you're going to find, since all copies of the film are bootlegs likely sourced off of one of the Laserdisc iterations. The version that I have was also from Demonoid, and I'm afraid it is the best quality version of the 2 or 3 I have seen. There was one I got a few years ago that was sourced from the VHS version, and was enough to make you rip out your eyes.
So, I know this is difficult to watch, but it's as good as it gets right now until Apple releases the re-mastered version. Hopefully they will include all of the deleted footage and someone can restore 'Let It Be' to its' original 200+ minute version - and finally solve the mystery as to why the Beatles really broke up. I have my suspicions that it had nothing to do with Yoko Ono!
If you're interested, I made a cover for Let It Be, specifically for the Demonoid version which I downloaded. Here it is, if you want the high-res version, let me know. I have also designed replacement covers for the other Beatles films, to match. Cheers.
