Agreed it's super heavy for what it is, which isn't a terrible thing I had the same idea for my little stubby m4 build. That said I went to a normal stock, then a side folder and it became more of a pistol, then I built an actual m4 pistol etc. Right now the stubby is down with either a stripped gear or piston haven't torn it apart to figure out the failure yet. That said my son generally uses it and we didn't play this winter. So one of these days I'll tear into it and figure out what happened. But with him using it I've kinda fiddled with what stock fits him actually thinking about it that may be the stock that is on there again;)
It's not bad, it's honestly just a hair shorter than I'd like but I'm also pretty big at 6'2 so that plays a role. The theory is good just not sure the actual function is there. I think my favorite was the side folder functionally, but battery storage was the issue there, I built a 3d printed battery box for it that fit within that stock but at the time honestly I wasn't very good with CAD by contrast. So likely I'll redo that one of these days and retro fit back to the side folder with an 11.1v lipo and once I rebuild the box I'll toss in a high torque neo motor and make a semi fast shooting lower FPS platform out of it.
Luke