My LC9s is on it's way back to Ruger...permanently. I say that up front so you'll not think I'm being sneaky or something.
I loved the LC9s and selected it mostly for its trigger...the trigger is miles better than that on the Shield. S&W has never been able to get pistol triggers right, IMHO. The DA/SA pistol I had from S&W back in the late 80's or early 90's had a decent DA pull but SA was terrible with tons of creep, etc. I've not been impressed with their triggers on striker-fired pistols, either. It's ironic because both the DA and SA modes are pretty good on their DA revolvers.
Anyway, as I said I loved the trigger on the LC9s...it was better than a stock OOB Glock...and better then the trigger on my new Glock 26 even after doing a "carry" action job on the latter (i.e. no changes in components, just lightly stoning and polishing the surfaces).
On the first range trip I discovered that the LC9s really didn't like wide mouthed (i.e. "defensive") hollow points. They did not feed well. A few minutes with a felt wheel with some Flitz turned the ladder below the chamber into something resembling a feed ramp, and thereafter my feed problems were solved. Strike one, because I shouldn't have had to do that, but at least it was something fixed easily enough and, assuming one has the sense God gave a goose, so they test the gun with their defensive carry ammo, it's not something that is going to be a surprise at a bad time.
Then my IWB holster came in and I discovered that the magazine would release in the holster every time I turned my torso as when getting in or out of the car, etc. After a lot of research I discovered that the USA magazines are known for that problem and even for releasing under recoil (though mine never did the latter). I bought some Italian magazines and they worked fine. Strike two against the gun, but again not something that was likely to go unnoticed until a crucial moment so I could live with it.
Then, I discovered that if I shot under "simulated stress" (shooting around barricades, one handed grip, etc.) the gun would jam with a horizontal FTE...frequently. I actually thought initially that it might be me, even though I've done that kind of shooting for years with guns that recoil harder than the LC9s, and have never had an issue. Then I noticed that the extractor was not even close to touching the shell and that it didn't appear to be damaged...but actually had poor geometry. This was not only the third strike...it was something that A) I could not fix my self and B) could have gone unnoticed until I needed the gun in an emergency. The gun worked flawlessly standing at a firing line with a good hold...but with that "weak" extractor it was a jam-o-matic under anything less than perfect circumstances.
I have since discovered that there are several others who have a similar problem with the extractor...and I'm almost certain that there is a bad batch of slides out there. The (very nice) lady at Ruger said that they had been making some improvements "based on feedback similar to yours" but I explained that I simply could not carry a weapon that I cannot depend on. I don't mind an occasional issue with a plinker or even a hunting gun...but my carry gun has got to work every (*&& time. Furthermore, since no one person can test a pistol, especially, under every circumstance then one must have confidence in the company producing the pistol, that they have done that kind of testing. Once I have lost confidence in the company that makes the gun...as I have in this case...I simply am not going to carry one.
Again...I really wish it was otherwise. Carrying the Glock 26 that I replaced the LC9s with is nowhere near as comfortable as carrying the LC9s was...but at least I know that every one of my Glocks always goes bang every time I pull the trigger right up until the magazine is empty.
At this point, the only way I would even consider carrying an LC9s again is if Ruger issues a recall on them AND convinces me that they know exactly what the problem was and that they have A) fixed that problem and B) finally done some actual testing on the guns to make sure that there aren't other "gotchas" lurking in the background just waiting for the worst possible moment to turn your firearm into a not very aerodynamic paperweight.
Back to the Shield...I actually considered getting a Shield to replace the LC9s in spite of the fact that I'm not crazy about the trigger. But I did a lot of research on the internet (something I wish I'd done before purchasing the LC9s) and found that there have been some similar issues with the Shield. Nowhere near the extent that there have been with the Ruger, especially when one considers that the Shield is probably outselling the Ruger by a large margin. But...when it comes to a carry gun even the somewhat less frequent extraction issues mentioned for the Shield are too many, IMHO.