I shoot the Shield 9mm better than some of the other guns I have. When I first got it I could not release the slide without extreme difficulty. There was nothing wrong with it, just stiff. After shooting a few hundred rounds and working it, dry firing and overall manipulation it loosened up. It's still a little tight but I'm sure another few trips to the range and it will be fine.
Right now I have an older 915, .380 BG, 9mm Shield, M&P 9 full size & M&P 45 full size. I love them all but shoot the shield best right now. I do need more range time, funny thing is I shoot the 45 better than the 9, go figure. I'm still figuring out which backstraps to use.
I haven't fired a lot of handguns but every time I do shoot something it just never feels as good as my S&Ws. Except for a good M1911, that's the first pistol I ever fired 40 years ago and it fits my hand great, the S&Ws are very similar. I even use the Magpul K2 grips on my ARs because they feel more like the S&W grip, especially the angle.