I got the PP750, I can say it is an impressive air pistol for the price point.
Externally I can confirm the fabrication is well beyond my expectations.
The internals are rough and noticeable when I am cocking/shooting.
A very first day I did a first surgery, dissembled it and one by one I deburred and polished the trigger and the cocking mechanism parts.
The design is logical and the precision is there on every piece, I measured some parts and the numbers are even, I believe the fabrication was done with stack up tolerances.
I decided that I will replace the hammer spring instead of clipping the original, I will add a hammer weight, and looking for a longer barrel in .22. Parts are on my list the question is only for what money and how fast I can get these. McMaster is my best choice but also open to suggestions.
The only thing I don't like is the 11mm dovetail, for $20 extra Artemis could build in (or at least include in a package) a picatinny rail, now I need to order and adapter from amazon (I guess my best option, can save me a trip to couple stores). I have some older dovetail rings but a shortest scope I can mount is a TenPoint crossbow scope on medium height. But I think a red dot or a prism scope would work the needs better.
I believe the next disassembly and replacing parts can be done in less then...5 minutes, a top. But I like to play with toys and I like to have nice and quality tools as well...this is my Lego.
My overall impression?

I am smiling. what I've got for my money is a good value.