Awesome, thanks! I went m90 over the other 5.56s because Zastava has history with the 5.56, more mag options, side rail, price, and adjustable gas should mean it's good with any 5.56 you might get. I will see how the standard polymer mag fits then maybe see if there are any sales next weekend.
I've never been sold on the need for the thicker stamped or milled receiver and don't like the weight, but people seem to want them. I don't have high hopes for availability of any Soviet calibers in the future and I've never been a big 7.62x39 or Wolf fan anyway.