Waters and crew took a different swing at the visuals, which added some good surprise elements, since the original tour's surprises in the show are now known to many people, and he updated many elements to reflect recent/current events. I think this was wise. Instead of holding off on projections on the wall until into the 2nd set, there were wall projections starting in the 1st song of the show. Projecting wall bricks onto the wall may sound redundant, but it led to many very cool, little mind-blowing moments.
I did miss Gilmour (no surprise) and the music seemed very smooth but without an edge.
I also missed the musical tightrope that you could often sense in Rick Wright's playing.
Roger also softened the edge of many of his characters when singing. The Doctor in Comfy Numb, for instance, seemed more benign - but if you accept this as different take on the material then it's OK.
The quad (or diamond) sound was not really noticible from our seats (16th row centerish) but they flew all the surround speakers, with many in the center, which I believe smeared the sound. There may have simply been less emphasis on the quad source materials for this tour. The use of quad sound-space in an arena was always a big pleasure for me at Pink Floyd concerts. I'd be interested in knowing if people in other seats had a great quad experience or not.
Lynn, who's never seen Floyd live, was spellbound and ecstatic about the concert.
I saw the original and kept my expectations reasonably low - and was very happy with the new alternative Wall theatrical experience.