To start just change you min and max values. I've read somewhere the min and max should differ by only 6 or 9. I can't remember which. If most of your ap's are at the min then bump them both down by 3. Then check coverage in those outlying areas (laundry room at end of hallway, tv room behind the mailboxes, etc)
In my opinion, don't turn on mode aware arm. I turned it on at request of support and had coverage holes just bloom out of nowhere. If it wasn't so annoying it would have been funny. You could map out the surrounding 10-20 ap's and just see the hole form over a period of time.