Hi,
    I've become interested in AR pistols. Anyone have this upper? Or what do people think of this as a start? Any other suggestions besides PSA?
https://kakindustry.com/upper-receiver-5-56-11-5-inch-barrel-9-8-inch-mlok-handguard

Thanks

No experience with those but looks nice.
I have a 15" AT3 Tactical complete upper on a 16" carbine and two of their AT3  SPEAR M-LOK Handguard for AR-15  that are 10.5" and 12". While people will probably flame me for not spending $300, I think these are quite a good product - they mate perfectly with their uppers, or will fit solidly on whatever upper you have. These are affordable but the fitment and finish is really good, AND their customers service is some of THE best out there. Really.
Additionally, some will say midlength is the thing, but I got a 16" midlength based reviews/research and found it to be a PITA. YMMV. It's finally dialed in and now shoots like a dream using a Kynshot buffer, and adjustable gas block. Were I to do it again, I'd get carbine length and call it a day. That's my .02

I rolled my own with mostly Anderson parts.  zero issues.  third ar that I had assembled.

I started with the carry space I wanted it to fit inside and worked backwards from there.  

Pantheon Arms Dolos takedown.

sba3, FAB defense folding grip.

10.5" barrel with MI flash can.

rest is standard ar.  

working on its replacement, 11.5" 6.8 spc.  I want meow muzzle energy.

People will probably give me hell about this but I order one as just a mag dumping range toy but it's quite nice and super cheap.
The one I bought: https://bkingsfirearms.com/shop/complete-upper-receivers/bkf-ar15-11-5-5-56-nato-govt-1-7-twist-carbine-length-barrel-w-9-875-slim-m-lok-rail/

Main page: https://bkingsfirearms.com/product-category/complete-upper-receivers/?wpf_filter_barrel-caliber=5-56x45mm-barrel&wpf_fbv=1

The upper didn't come with a BCG or charging handle but it's still an awesome deal.

If you go another inch longer of barrel and keep it in "pistol" configuration you would be able to add a vertical foregrip.  If that interests...

Hi,
   I thought any AR pistol couldn't have a vertical foregrip?

Once it reaches 26" OAL it can have a VFG making it an "Other Firearm".  It would then be designed to be fired with 2 hands so not a pistol but being 26" long its not concealable so not an AOW. Doesn't meet the definition of pistol, rifle, sbr, or AOW so generally referred to as other.

I think Bkingsfirearms is very underrated.  Quality is good.  Prices are fantastic.  Their private label barrels are likely Ballistic Advantage.  Everything I have purchased from them has been great.   Same with KAK.  I don't think the OP would be disappointed with either company.