Well, problems already.
The extractor springs I got from Midwest Gun Works don't work in the 2.0 slides. They only showed one extractor spring and I assumed it was for 1.0 and 2.0 guns. Nope. They will not fit down into the pocket hole in the slide. No amount of pushing, shoving, twisting, or leaning the springs will get them to drop down in that pocket hole.
Edited to add = while putting stuff away I picked up my latest order paperwork from Numrich and in spite of my forgetfulness I saw I'd ordered a 2.0 Shield extractor spring. Started digging through the pile of little ziploc bags and there it was, just like the picture on the Numrich site, red tinted and 6 coils. Dropped right into the pocket hole in the slide and I put the extractor on a minute or so later. Just need to trim the excess roll pin where it sticks out in the slide cut for the optic. Gonna order a coulple more anyway as the spares for the other pistols won't fit those 4" 2.0 Shield slides. I don't mind being lucky.
Went to the Numrich site and they show a difference between the 1.0 Shield and 2.0 Shield extractor springs. The 1.0 is like the ones I got from Numrich (the picture anyway) and have 4 coils. The 2.0 extractor springs (the picture) shows a spring with 6 coils and in the side by side pictures the 2.0 appears to be a smaller diameter wire as well.
Now to order 2.0 extractor springs from Numrich.
For info, neither web site/vendor shows a full size M&P 2.0 extractor spring. Only the 1.0 extractor springs. Don't know if they are the same or not.
Still learning. Problem is, next year I'll remember they were different but won't remember which vendor I got the right ones from.
On the brighter side, the striker spring guide, striker assembly, striker block/spring/spacer and rear sight are in the slide. As is the aftermarket rear cover with the US Flag on it.
The front sight is going to take some "fitting on the stone to reduce it's size enough to slide into the slide cut. Not unfamiliar with that. Every CZ front sight I've installed has had to have metal removed to slide in without a 10 lb. sledgehammer.
Oh, as others have stated, the striker block would not fully slide down into the hole in the slide. Found burrs on the inside surfaces of the holes. Got rid of them and got it working.