I have PSAs, Aero M5s, and some random ones. They all run great; some took more tuning and break-in than others:

I'm selling off most of my PSA stuff. Their complete uppers worked fine, but they didn't have fluted barrels and they were heavy.

I like the Aero M5 platform the best, and I would definitely recommend it as the foundation to any build. I have some with both the enhanced upper receiver and handguard and some with the regular threaded receiver and Atlas in different configurations from 16-22".

Notes:

1. 7.52x51 you don't need an adjustable gas block, but it is good to have one. 6.5CM you definitely need it. I use the Superlative Gas Block on all of them; works great!
2. The Aero enhanced carbine 308 complete buffer assembly with a Magpul STR stock with pad works great especially if you plan to use it for long range. It takes a little break-in to get it working right, but not a big deal.
3. I mostly have Geissele SSAE triggers but that is personal preference.
4. I use the KAK double plunger BCG, and they work great!
5. I use Wilson Combat SS and Faxon Match barrels....never had a problem with any of them and they are all sub MOA builds.
6. I do have some ultra light weight builds with Faxon pencil barrels. They are more picky with ammunition choice.

In short; building it yourself is not an issue if you go about it the right way.

Attaching a pic with a couple Aero M5 builds: a 20" 6.5CM with the enhanced upper I use for long range, and a 16" 308 with the Atlas upper.

Click image for larger version. 

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