I am going to get either the meng abrahms tusk or the dragon abrahms M1A2 SEP 3536 (this is the V1 SEP, not newer V2). It will be basically the same price. $5 more for the meng. The dragon is a rerelease, so it will not come with the metal barrel, but I still think the plastic many-part barrel would be easier to build cleanly than the two-part barrel split vertically in the meng.
I would probably not buy an am metal barrel.

But I was wondering about how the other plastic compares. The tusk is a nice bonus, but it isn't absolutely necessary.

So anyone have experience with both kits? I've read good reviews for both.

Just got done reading the Moxing 4 kit comparison. More specifically, the google translation of it, since it was all in chinese. Google did't do so well. Dragon == Veyron. RFM == catcher && wheat field.

Basically, they both look pretty good. Each have their advantages, but can one be said to be more accurate?

Look here:
http://vodnik.net/pages/M1A2comp/m1a2comp_01.htm

By and large and far and away the most comprehensive review of the kit's you want to know about. At least it will be.