Well, if I'm honest, the DX320 Max looks very much like the 300Max, can't tell any differences in shape or bulk. Design-wise, I'll agree it's minimalist and plain (a little "brick" as some fans called it adoringly), but these are tastes, so fair enough. For me, it's the sound that matters. Not even weight and portability faze me (I'll even wear it while working out, inside a special pack, and take it with me when out and about in a small rucksack).
Another needed feature is the ablity to leave it plugged in without effecting the battery would be a huge plus. That was one of my gripes with the dual battery, never last a whole day for me thus the DX320 Edition X saved the day.