Never tried their 1911 mags but the ones I have for my BHP, P08 Luger and 5906 work great.
At that price, jump on them.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together.
You'll remember the quality of a gun long after you forget how much you paid for it.
US Army 1966-69, VFW Life Member, Retired Geek