^
I have yet to do a critical comparison with the DX200 but I'm guessing upon initial impressions the AR-M2 is already more punchy.
As for the case it is AR branded packaging and I don't know actual manufacturer. The case fits perfect, not bulky at all, and looks sharp. Perhaps you can see it in the included pic. The screen protector is nothing special and after a couple of attempts at putting it on straight and dust-free to no avail I gave up.
I always demo my new acquired DAPs & phones with 2 albums. Dido has a good (imo) vocal, and a well-rounded mix of acoustic, pop, and techno elements. Jane's just kicks everything into high gear. After a few hours listening with ONLY these two in FLAC I can already say this is one nice sounding unit. Using EX1000 with stock cable for all the listening so far.
The only con so far with the AR-M2 is I wish it had a digital volume level display to coincide with the volume wheel.