Hmmm, that's tight, but does seem about the same as my old CR and drum room. You might consider making it a 1-room setup as 1 large room might be better than 2 rooms that are too small. Going back to splitting the space in 2, you could make the dividing wall a bit off-square to cut down on parallel surfaces. Draw out the main shape and start messing with it
(better to screw up on paper a few times before screwing up the real thing
). Sure would be nice to have 1 or 2 amp closets...........