Well what do you want from the sub? The SX and the Mag are completely different subs. The mag is shallow, requiring a very small box, and is generally an SQ sub that can get loud. The SX does not sound as clean as the new Mags should, but are great for SPL purposes (I'm saying should because so far nobody has had one of the production mags, and probably won't until sometime in early october. They've had TONS of problems with their shipping company, lol.)
Also, how much power do you plan on feeding them?