I've been playing on Deadly (0). It's jarring to move in and out of epic/book instances where the difficulty level is set to normal. "...but the challenge might be great!" Um, actually, that's when my toon becomes a god for a little while. And that's not even counting the Inspiration buff! Playing one of my characters on a "regular" server makes me laugh a bit now, with pre-LI crafted gear or with LIs, I overkill pretty much everything in one shot and am nearly impossible to defeat except via some "You are dead now because you didn't interrupt this"-type mechanic. Skirmishes are a pain, no easy Marks for me on Treebeard or Shadowfax, and the Skirmishes that are required for some of the epic/book quests are much more challenging than any other solo activities and not always in a good way.
I still hate the explosions, they just don't feel right plus they have almost no impact on the play of some characters and are borderline crippling to others. Deadly (0) has otherwise been great, I've really been enjoying it. The new LI system is far superior to the old for someone like me who hadn't yet invested much time or other resources in the old system, although I wish there were more straight Ancient Script rewards instead of random traceries or other things – give us AS, we can then barter for what we want instead of crossing our fingers and hoping for something useful when we open a reward box.
I agree about Deadly (0)...I tried Deadly (+1) for a short while...a very short while...and decided I didn't want to be that aggravated. I don't play this game because I have fantastic eye-hand coordination... that's much too twitchy for me.
And about the Skirmishes...yes, they now become much more difficult than previously... I hated Defense of the 21st Hall.