Lords of the Lost supported them on the last European tour and they were pretty awful - anything's better than that. I'd love to see The Hu support, as they're a band I like but wouldn't go out of my way to see, I'd be more than happy if they were announced as support for a band I was already seeing.
I saw Avatar supporting Halestorm, and yes, they're brilliant. Really funny and upstaged the headliners.