Thumbs Up on the Holosun 507C and M&P9 Compact
On a recent trip to my local range with the CSX, I thought I would try one of the rental pistols, an FN9C, that had a Holosun 507C Optical sight with green reticle. I was incredibly impressed with the Holosun, seemed much easier, at least for me, to find the reticle and acquire the target than traditional red dot sights I had tried. I was so impressed with the Holosun 507C that I bought one the same day (no, I do not own stock in the company). The 507C gives you 3 choices of reticles to switch between, circle and dot, circle only, dot only, and it is very bright and easy to see.
I just mounted it on the S&W M&P 9 Compact 4 inch. As I very much like the curved hinged trigger on my Shield PC, I was initially a little apprehensive about the flat trigger on the M&P Compact but now decided that I do like it, very nice trgger pull, typical of what we have come to expect from S&W; the only difference being the trigger action was excellent right out of the box and did not take a few rounds to smooth out like some of my previous S&W, 3914, Shield, CS9, CSX, etc.
With regard to sights co-witnessing, the M&P 9C came with what appear to be tall suppressor style sights, and they show up fine in only the lower portion of the Holosun Optic window, they do not interfere at all with the optics reticle, as the iron sights, even though they appear a bit taller than regular S&W Novak style sights, they only appear, should you need them, in the lower portion of the optic window.