Not really familiar with them though have just had a listen on spotify and can imagine them being perfect in the right conditions (i.e. a balmy night in August under the stars rather than standing in heavy drizzle). Surprised they've been chosen as headliners though. Better than last year's Friday night headliners!
The right to bear arms is only slightly less ludicrous than the right to arm bears.
I think they will definitely be HL material and anyone who f*** off while they play will be named a donkey. By me. As the GM is a medium sized festival, it fits perfectly. As any other post rockish band, I find the music to be very endearing, emotional and excellent live. I hope that the sound does them justice though. And I hope for some light show or something. If you don't know them, think MONO, Mogwai, Sigur Ros.