My problem with David's solo work is that to my ears in terms of chords, melody, harmony, its starting to sound like he's rewriting the same song over and over. Don't get me wrong, loved much of his work from the giver onwards, its just sounding all the same, which would be fine if you hadn't listened to anything previous. I don't yet get the same thing with Mark. There's been some self referencing and the occasional pinch from older work but he somehow manages to steer clear of such pitfalls. His character driven songs are transcendent, they exist in their own little universes, their own sonic space if you will.....