I was going apex my M&Ps but I had older ones and was going to have to change the sear blocks. I ended up trying a Glock 17 and sold the M&Ps. I would get the kit minus the trigger.
No need to ship from an FFL. Needs to be shipped to an FFL.
Long Guns can go usps mail from an individual to an FFL and you do not have to inform the postal service that it contains a firearm.
Long Guns can also go UPS and FEDEX Ground from an individual to an FFL and you do have to inform them...
I liked M&P9s and 9cs pretty good. I broke down and bought a G17. I ended up selling the M&Ps. I still think there are lots of positives of that platform. I never did like the G19. The grooves didn't fit my fingers as well as the G17.