I used to have that Mini UZI also and it was kinda nice, though completely un-upgradeable and impractical for gaming because of the velocity. The nicest thing about classics (and I use the term loosely when referring to modern Escorts) is if you're shooting too hot or too slow, you make an adjustment on your regulator and you're good to go. With an AEG you need to open the gearbox and change a spring which cannot be fine tuned. With a fixed-output gun like the KWC Mini UZI - or ANY gas-in-the-mag gun for that matter - you have no options beyond permanent valve modification or other expensive upgrades to increase power that also cannot be tuned.
For example, I'll run my SP M16 around 150-160 psi which puts it around 380-390 fps with a 0.20g; perfect for outdoors. When I go to Xtreme Tactics their limit is 350 fps, so I drop it down to 120 psi and I'm down to 330-340 fps. Takes all of five seconds on the Palmer's stabilizer with an allen key.
The biggest problem with Escort guns is their extremely limited production, and the fact that the main English-speaking contact there is an unreliable flake who takes six months to ship you parts. Those of you who've chatted with me know of whom I speak. Thankfully a chap in Hong Kong has stepped in to fill the void and is making all manner of parts for these guns, and they are incredible! I've got a stainless steel 1-piece valve in my SP along with a stainless buffer screw; steel bolt is next!
By the way, if you plan on getting into Escorts/classics you should have fairly deep pockets. The stainless valve alone cost me $140 USD.