Could we get drawings or photos of the old vs. new versions?

I just bought my M&P9 FS in January. SN HAF70**, with a test fire date of 10-08-12, so it's fairly recent. I do feel a slight "hitch" at the reset point, but it's not a very positive indicator, and I have nothing to compare it to to know if it's any different. It would be helpful if S&W could give us serial numbers or manufacturing dates to tell us when updates were made. This might easily become an issue when ordering replacement parts from S&W, let alone knowing what aftermarket parts will work or not.

I had the gun out to the range for the first time yesterday. I don't care for the trigger action AT ALL! Looking closely at some the engagement surfaces in the trigger assembly, I can see why. Nothing has a proper final finish! I can understand the complaints I see on the forums and why so many are swapping in after-market parts, but I'll try some simple polishing first on this one before I start replacing parts and experimenting with different spring values.

The gun was reliable, fits my hand comfortably, and points "naturally". I think it's just going to take a little "tuning" to make it right.