I'm basing this on hundreds of dungeon runs on multiple characters up to The Frozen Heart. The Wolf Den was a wipe 100% of the time, but the other mid level dungeons weren't much better.
No, I love playing with others, but it was nice when I could just jump on at any time, hit the join button, and start playing. What I'm asking is if that's possible with any of the higher dungeons. If not (and I knew it was a long shot), I'll just wait for the perfect cookie-cutter guild group. That's the IT in me. I can't…