They look cheap. They feel cheap. You can't replace the trigger guard. Polymer has a shelf life. Take a 20 year old Glock in for service. How many times have you seen folks take in Gen 1 and 2 Glocks only to have Glock tell them their frame is being replaced because it's no longer safe to fire? It makes no sense to shave off 30-40 bucks on a 600-1000 dollar rifle build by using a receiver that devalues the entire rifle to the actual value of the upper. That's all I'd pay for a poly lower AR. Whatever the upper is worth. I'd figure any internal parts salvaged as bonus and payment for my time to disassemble and scrap the plastic lower.

