Nah, we don't make their stuff... J/K, I'm not in any way affiliated with Quentin Defense but Sun Devil does claim to make their receivers from raw billets so I doubt QD has much to do with Sun Devil other than that they're in adjoining cities - Gilbert and Mesa AZ. Either company makes nice stuff so look at both as they are comparable in features and styling.
I do have an 80% Sun Devil lower and can say the manufacturing quality is excellent. Some day I need to hog out the magwell and trigger area and finish the darn thing.
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