I've got a friend who's first AR was an Armalite M4C preban. I was impressed with it's quality, it's every bit as good as any of my Colts and I would judge it better then my Bushmasters. I don't really care for the short 11" barrel and long permanently attached flash hider of the M4C though.
I gather from your profile you're in the St Louis area, my friend with the Armalite lives in Millstadt and I'm East of there. If you want to look it over and shoot it contact me privately, we're getting ready to have another shoot soon.