The ZF-5 is a semi-auto MP5 style platform featuring a roller-delayed blowback operating system, Pic rail, & a cold hammer-forged barrel. Get your American-made MP5 at Zenith Firearms.
I have a CAI AP-5 made in Turkey and it runs 100% with everything I've fed it.....And I've fed it a lot.
I got lucky and found a half dozen each HK mags (20-30 rds) for cheap but the two Turk mags that came with it work just fine.....I really like the HK 20-rounders. The Turks build good MP-5 clones.
I put a SB side folding brace on mine for the time being......I plan to stamp it but I'm going to do suppressor and SBR stamps at the same time.
As far as reviews on the ZF-5 they seem OK and in hand I'd not say they were any better fit and finish-wise than than AP-5 but they are Virginia-made.....If I did not already have the AP-5 I'd spring for the Zenith since they lowered their prices.
They use rebranded Korean KCI mags. I've had good luck with their M1 Carbine mags so I suspect they are GTG. I've heard that you need to clean the mag body good first.....They are around $50.00 each though Atlantic has two-packs for $89.00.....$54 each from Zenith.