Mine was $530, apex trigger would add $90. But for this model I honestly don't think I am going to do the APEX trigger. A heavy trigger that is smooth is fine to me, I used the APEX kit mostly for the grit. I would also say that after the APEX kit it's not apples to apples, the M&P trigger would be a good deal better than the Glock at that point (just IMO).
I got my M&P9c five years ago. At first, its trigger was kinda stiff and I thought I wasn't going to warm up to the pistol as a result. But the accuracy was good and it fit my hand so well I stuck with it. After a few hundred rounds, that trigger smoothed out very nicely and I now have absolutely no complaints.
I've never shot the American Eagle ammo, so can't comment on the ejection issue. I shoot mostly Winchester White Box and have never experienced a problem. Could be that your extractor claw might need a teensy little bit of polishing.