I recently downgraded Highlander from Blu-ray back to DVD in my collection.

I'm not sure if it's solely the higher resolution or some other difference in the video but at the end, when Connor is floating and being molested by animated ghoulies, the wires holding him up were painfully visible. I knew they were there, obviously, but I never could really see them until I watched the BD and it was like I was suddenly watching "Flying Lessons" from Monty Python's Flying Circus. I know these things are part of how movies were made back then and couldn't always be hidden, but in this particular version of Highlander it just grabbed me by the eyes and screamed "Look at me!"

Perhaps some films just aren't meant to be seen in HD.

But aside from that, I'd still recommend the Immortal Edition DVD above the Blu-ray because of the Queen music videos included on the disc.