Upon first listen you don't notice much difference to the first CD release, but as you listen more closely you can pick out things much more easily than on the original CD's (such as a murmer of speach during the string introduction on 'All You Need Is Love', and bongos (?) throughout most of 'Penny Lane'.
Having not heard any of the other remasters I have nothing to compare this to (although I have a couple on order!), but they definately sound crisper and cleaner than before.
As for the stereo mixing of the vocals on one side and the drums etc. on the other, that was obviously the way things were done in 1967 and was how the Beatles wanted it to sound, I see no reason to change this for the new releases, after all they are remasters, not remixes.
Also there's an error on the disc label-under the track listing it says 'Let It Be Mini-Documentary', whilst it is in fact the correct one on the disc when you watch it on your PC! Apple/EMI are likely to correct this on future pressings, so get it now and it may be worth something in years to come!