Help me treat a difficult room

It's not bad at all actually. Every other surface is basically treated to a point where having one 'live' surface in the room isn't so much of a bad thing anymore. If I were to treat up there it would turn into an absolute box... very surreal sounding with barely any reflections at the mix position, except those created by the furniture. You're welcome to come by sometime and have a listen when the ASP8s get back.
 
I'm trying to get that information from Rode/Event right now. The higher the ceilings the better off you are generally. It's the small ones that cause the big problems. Though it all depends on the dimensions of the room. If you have 2 or 3 dimensions relatively close in length to each other, then acoustics start backdooring you pretty hard. You want 3 distinctly different sizes.
 
Yeah, I'm stuck with a long rectangular room, I knew that wouldn't be ideal, as long as the fact that the walls aren't covered from floor to ceiling isn't too much of a problem all is good.

I've actually worked out a good way to get the ceiling treated. It involves only one hole going into the ceiling and the rest is using the fittings in the room (door frame + curtain rod) to suspend some covered rockwool. It will hang about 45mm from the ceiling, 1m from ear level at the listening position. The only down side is that I will have to use some really light stuff so it doesn't all fall and fuck up the room or my gear in the process.