If you go with a piped .50, get the AAC... you will want to save every ounce you can up front with a .50.
AAC will save you about a half an ounce I think. A pipe is mandatory IMO with a Dust and a .50, it will solve your CG problems.
It will balance perfectly with a muffled .35 and the battery behind the servo's.
Other than that, the AAC's are more user friendly I think. They tend to resist the occasional lean run slightly better. That doesn't mean you can't smoke 'em.
Edit: try to put the throttle servo in between the elevon servo's, it will stand up better to the abuse of a 50 on full song. I've killed a few servo's on Dusts with them glued to the right center rib just behind the engine. It is a harsh environment for any servo.
Last edited by Rudeboy; 12-29-2014 at 04:33 PM.