Sorry if this has already been asked. I'm looking for someone to take me to school here. I have aero lowers, like em alot. never any issues. Buddy of mine has some spikes lowers. Never any issues. But I'm looking at things like knights armament stripped lowers for over $200. Are they worth double the cost of an aero? Also, what's the difference? Aero and KAC are both made of forged 7075T aluminum, and if the aero lower is machined within spec, why is the Knights lower and others put on such a higher pedestal?