Like dirtmcgirt asked, have you checked out an MP5 at all? They truly are awesome guns. I have one and I freaking love the thing. Until I had it they had always been a dream gun of mine, and now that I have it they really do live up to the hype. It shoots great, and the recoil is a joke. The only bad thing about an MP5 is they price the command. If you want a good MP5 then you can't go wrong with the Atlantic Firearms Omega guns, Zenith Z-series, or the new PTR MP5s.
That being said, I also used to own a CZ Scorpion (which I loved too). I don't know what you disliked about the Scorpion, but in terms of functionality they are very much just like a modern MP5 with better ergonomics. Just something to keep in mind.
The MPX is cool but isn't really my thing. I've shot one and thought it just felt like an overpriced 9mm AR. But if you like the AR platform then the MPX is a solid gun.
I've never shot or even handled a KRISS Vector, so I can't speak about those.
I’m actually leaning towards the sub 2000, affordable and has generally favorable reviews. Plus, I really like the folding factor. Lots of after market mods to upgrade it with too.
I bought a Vector 9mm pistol purely from video game nostalgia. It's overpriced for what it is and at almost 7lb empty, too heavy as well. Already the hinge for the folder is starting to feel a little loose. If you put a can or a comp on a Glock 17 and use an Endo Tactical adapter + brace you'll get a similar level of recoil.
At first I wasn't impressed with the Scorpion but after handling one with a Tailhook, its /only/ shortcoming in my mind is not using glock mags, and with how its built I'll be surprised if at some point someone doesn't make a new lower for it to accept those. Practically speaking if you want a "subgun" the Scorpion is the best way. Awesome irons out of the box, light, and solid.
The PC seems to be gaining popularity quickly. There is a FB group you can check out. Upgrade parts are already coming out. Could see a lot of stuff for them as popularity rises. The more of them out there, the more aftermarket stuff you will get and there is going to be a lot more of them out there thaner most other options.
Mechtechs are cool but heavy and they don't lock back on last round.
The Scorpion has a heavy trigger out the box. Buy some springs, break out a file and a dremel with some polishing compound, and then go to work and it'll turn out pretty decent.
Ruger PC is a solid choice too.
The B&T 9mms are pretty nice shooters as well and top quality.
https://www.budsgunshop.com/catalog/...CE+SIDE+CHARGE
anyone heard of this 10mm? not much info about it out there