Here are some pictures of guns that I own that fall into the PDW category. First, an SBR'ed HK94 and an AK SBR underfolder. Both were owned long before the riots or the Covid situation.
The HK is an HK94 that was SBR'ed and worked on by S&H gunsmithing in Oklahoma. S&H Gunsmithing is very well known for their work on HKs as well as a variety of other guns-especially NFA firearms. The barrel was shortened to MP-5 length, a 3 lug adapter was fashioned, and a paddle magazine release was added so the gun is like a semiauto MP5. And of course there is a surefire light.
The AK SBR Underfolder was something I stumbled upon in my local gun store in 2014. It is 7.62x39, has an 8.75" barrel, and was manufactured by Vector, as indicated by the receiver. I really don't have a lot of information on Vector AK SBR underfolders. But the gun shoots smoothly with no issues. Of course it is blasty with the short barrel and muzzle brake/booster and can have a varying amount of muzzle flash--sometimes it is pretty big. It varies between shots from the same box of ammo. I have heard different explanations for this phenomenon. I remember reading that unburnt powder can accumulate in the muzzle device from shot to shot, and then spark. The sights aren't great--even by AK standards. The rear sight consists of L-type flip sight with a V-notch on each leg of the L. Both V notches are very narrow, which makes it hard to get any type of good sight picture with the front sight.
Next is the HK SP5K.
I purchased it this past spring. Since it had an optic rail, I bought it with the intention of mounting one. I chose the Aimpoint T-1. I wanted to go with a 4 M.O.A. dot, and a friend had a used T-1 available. While I really like having the Aimpoint on it, the rail attaches in a way where you can easily gouge your hand if you are not careful when pulling back the charging handle. Below is a picture comparing it in size to the SBR'ed HK94: