Vandie 1c or Maggie MMG?

I would never say Magnepan in that size room, I owned the MMG and its a nice speaker but the Vandy will work better for you right now, if you ever move then maybe move into Magnepan but once a Vandersteen man then many times you will just move up to better Vandersteens.

I have both and a I like the Vandies better in any situation.

The issue with Maggies will be placement - they need to be at least 2-3' out from the rear wall, and a couple of feet in from the side walls, which may be a problem in a small room. My old MG-IIAs (roughly the size of 1.6s, so bigger than the MMGs) are 5' out from the rear in my 13'x20' room, and 3' in from the side walls. I love the Maggie sound, but they are difficult to "blend in" to anything other than a dedicated room (unless you have an understanding 'significant other').

I've owned MMG's and 1.5's, as well as 1c's, 2ce's and 3a Signatures. I think the Vandies would work best. The Maggies are tough to place and can sound pretty harsh on poorly recorded/produced music (60's & 70's rock).

Like I said earlier and seems to be corroborated by some others, regardless of their comparative qualities, your room is simply not ideal for Maggies, the 1Cs will work. Whether you then move on up the Vandy line, many do - graduating through the 2s, 3s, and 5s or swithch to Maggies, which many also love - will depend on your taste, room, and electronics. With the room you have, I don't think you have much of a choice between the two, the VS are simply a better match in you situation.