For the record, I would absolutely love an Eldar version of Only War.

They were starting to show their age three years ago. These days, the Dark Heresy rules are simply poor.

Maybe it's just me, but DH rules seem ok to me. Sure, there's some rules begging for alteration, but that's easily done on your own. I've been running DH campaigns for a while now - my few homebrew rules are all that required for a clean game.

DH works perfectly well in my experience with the exception of the full-auto issue.

The psychic power system is actually the best of the 40K line in my opinion.