I really liked the new edit conflict interface (the one with the radio buttons), but even with that, edit conflicts in discussions were still a pain. It was great for articles or editing the same text, but when adding to a discussion, I found myself, more often than not, just reopening the edit-interface and adding my text again because it was easier. I just got this new paragraph-based interface and it's amazing. I'm really excited about this feature and am thankful to everyone who is working on it!
My only suggestion is to add more helpful tooltips or labels. Having seen the previous radio-button interface, this one confused me a bit and it took me some time to figure out what would happen when I hit "publish". I think RoySmith gave a more detailed description below which was similar to my confusion. I remember when I first got the interface with the radio buttons that there were blue dots that were part of a tutorial or something? Could those be reintroduced?