Looks great!
I played a gig in a room like that with a steel drum band a few years back. So much reflected sound that it sounded like four people banging out chords on pianos instead of a couple of steel drums. Fun gig, regardless.
If you can get some distance between you and your cabinet, you'll better be able to judge how it sounds in the room. In a big room like that, though, it's always going to be mushy and inarticulate unless you're staring into the speaker cabinet at close range.
John