I'm referring to the ejector, not extractor. I should have stipulated that very clearly.

When new, my M&P's ejector was too far away from the bolt to allow reliable ejection of spent cases. Spent cases would be crushed by the bolt with regularity (2-5 out of 25). Sent it back to S&W, who tweaked the ejector and it's been great ever since. This is a fix that the end user can do pretty easily, but I wanted them to do it (it was new, dangit).

S&W may have changed the extractor in the Sport models, but I don't know that for certain. Again, I had a problem with ejection, not extraction.