The programmer was seen as a step forward! The trigger/fire selector thing came first in programmable mosfets (my own SCAR L has a BTC Chimera in it and that's how you program it) so being able to have a box with lights and clear selections was a bonus. Bit like the Programming card for the Gate Warfet.
I've used the double mag high caps, they're OK. The dummy bullet slide on the second mag can be a bit sketchy and the winder goes front to back (where most go back to front) so that can catch you out. Otherwise, yeah good.
Just to throw some confusion into the ring, if you want a HiCapa that ,looks like a 1911 you need a Para Ordnance P14 https://wolfarmouries.co.uk/we-p14-gbb-pistol-black.html
ISTR the TM had M&P markings though
Scratch that, I've seen it with both! Probably depends on when it was made.
That would in fact answer the question. If it is in fact the TM then it should say Made in Japan, Tokyo Marui, ASGK
Can you get a close up of the right hand side of the gun? What do the markings just behind the mag release say?
Any idea roughly how old it is?
Looks like it might be an old JG/Golden Eagle M4SS
Assuming it works OK you might get £75-100 for it.
For something like a DMR where you want super fast trigger response on Semi then yes, precocking does make a difference. On an MP5? Probably pointless.