I tried the Decware diagonal setup (when I had the place to myself) and it seemed to help.
I agree with the woofer/tweeter integration with the Hawthorne 15 inchers, but the 10 inchers are better in that regard (trade that for deep bass). I've heard all their models and really think Hawthorne has the below $2,000 USD O.B. market cornered.
Another suggestion for cheap/efficient (and point source) is Pi speakers. Wayne sells primarily kits, but the 2 Pi tower can be done with pre-laminated MDF shelves as I recall. But from what I've found from auditions they (more so than most speakers) want to be away from the wall (unless you go for one of their corner models).