Depends, if it's your first AR, I would actually recommend getting the ACI and spend the left over money on accessories and ammo. You'll get more value that way imo if you're a new shooter unless you plan to go straight to putting a can on the 12.5" Zion right away. 12.5" is not the most pleasant to shoot unsuppressed

The ACI-15 also rumour to have BA barrel although IDK how true that rumour is. I do have one ACI-15 that I use as loaner for my friends and just throw around the truck and don't care about. It very nice and great value for what you paid. An equivalent PSA would probably run you around $550-ish after taxes and shipping

Now, if you're the "Buy once Cry Once" type then I'd recommend another route completely.

Which is to build or at least source higher quality parts. You'll have to do your own research to decide what is best for your wallet, needs vs wants, as well as how often you'll realistically train with the rifle. A lot of people buy very expensive, nice guns just to shoot them once or twice a year and make them safe queens which is a waste imo

You can just copy my "Buy once cry Once" build in my post history which is around $3.5k all in and call it a day.

That build should be good enough for 99.9% of shooters out there. Even the door kickers special operators imo