Again, I can only go by personal experience. I've used Aeroprecision and Spike's Tactical lowers for four AR15 builds and one AR10 build. All have performed without issue. Several of these guns have thousands of rounds through them. So, my experience is 5 for 5. Now if someone else has personal experience with Aeroprecision or Spike's Tactical where they bought a lower that was out of spec. and simply didn't work for their build and the company was unwilling to make it right, I'm more than interested to hear about it. But if it's just your opinion that a $250 lower is better than a $70 lower because ... well it cost $180 more. That isn't really all that persuasive.
Ultimately, it's your money and you can spend it how you want. To me, spending $200-250 on a stripped lower when a blemished lower I paid $50-70 for performs exactly the same is a waste of money. Same with a lower parts kit from a known mfg. Again, I've never had a detent or bolt catch fail. I'd rather take the money I save building a lower and use it to buy a high quality upper. Or a good quality scope. Or ammo.
Nothing happens in a vacuum. 4 builds is hardly enough to have any resemblance of statistical significance. You may very well have products that work for you. You may also have issues you are not aware of.
People tend to live in their own little bubble and ignore what we know as industry whole.
There is a whole spectrum of knowledge and experience. Not everyone is the same.
The AR believe it or not, is a complex mechanical system with ALOT of variables that can go from do nothing to complete failure. You have hundreds of manufactures all building various components, to different specs, with different materials , with varying amounts of quality control, with different monkeys running the machines, with assemblers who many times do it differently, requiring the gun to run in wildly different environments with different magazines and ammo.
It is more a testament to the inherent design that we are able to make this work at all.
Slapping parts together may result in a perfectly functioning weapon. It may also result in a weapon that appear to work but has serious issues that will show up when your round count goes up, it gets dirty, you change ammo, run it dry,ect.
In order to ensure a weapon will run, you stick to quality, known components that have been proven to work together.
If you were to take the time, you can find numerous issues on the net from people having issues with many of the products mentioned. Not that the top manufactures aren't capable of letting a bad item through, however the frequency is a fraction of a fraction of what many manufactures consider acceptable.
Cheap parts are cheap for a reason. They use cheaper materials, cheaper machinery, cheaper tooling, Let the tooling wear longer before replacement, Do less or no QC, Instead of scraping bad parts, trying to salvage them/sell to discount sellers, Do little to no R&D to ensure the parts combination is durable/reliable over its life cycle, Employ low firearm IQ people, source the cheapest sub components they can, ect.
Quality costs money. Colt, BCM, FN, LMT & KAC all devote alot of time and money to ensuring their products come out ready to perform. They spend money in places most don't even have a person doing that function. KAC probably spends more on R&D than Spikes , Aero, PSA & Anderson does in a year combined, with a much much lower vollume. They do this becuase in the 20-30-50 years they have been producing hard use combat weapons, they know what needs to be done to ensure the end user can trust their life to this tool. You think they want to run pin gauges through lowers and barrels to ensure it was done correctly, even thought they know the tool path and tooling is good to go? Maybe through experience, they know a bit more than your cheap poverty pony or PSA.
And then nothing is constant. What was a fantastic product 5 years ago may be trash today. Its common in the firearms world for companies to sell out their "brand" to cash in. What is trash today may end up being very high quality in the future. You need to have a pulse on the market as a whole, in combination with understanding the history of this platform and the firearms world to have a good understanding to be able to make informed decisions and smart choices.
