I did Metal Feed Ramp, Metal Trigger and Spring Kit.
I passed on the metal trigger guard, non-strip screws, charging handle, etc.
Shot last weekend, and it really turns the thing into a different gun.
IMO metal trigger and spring kit are MUST dos on this gun; doubt the metal feed ramp is necessary, but I opted to put it in since I'd have the gun apart.
I also took a drill bit and slightly enlarged the peep aperture on the stock sight.
Pro-Tip - be thoughtful about what upgrades you want to install; I only want to take that gun down that far ONCE. It's not Rubik's cube, but not something I want to be doing often. On reassembly, it is likely one of the spring legs pops out the back of the receiver slightly, creating a 1/16th of an inch gap in the back of the receiver/grip. Use a flat bladed screwdriver to push this spring back in as a last step while you're closing the halves of the receiver together - this step is shown in the MCarbo video, but is easily overlooked.
*** $$ savings ALET *** - You don't need the buffer collar wrench, just use cheap harbor freight rubber strap wrench - although it has threads, the collar doesn't really thread onto the back of the receiver, more of a push-fit. I used clear nail polish on the collar threads and all screw threads in lieu of blue loctite.
No pics, because mine is otherwise stock, the changes I made would not wow you in photo - they sure as hell would wow you if you were shooting bone stock and felt the difference in trigger pull.