Have a look at Nelson Pass slot loaded open baffle article. He used the Lowther PM6A. There is nothing wrong with the DX3. The only way to know is to listen to it, but make use of its strengths. You don't have to copy exactly what Nelson has done you could do something like 2x15 per speaker. Anyway don't worry too much just enjoy the ride you will learn a lot. If in the end you still don't like the DX3 you could always try the pm6a later or Audion Nirvana Alnico. Anyway I am quite confident you will like it when you build on its strengths.