I love my P-series, I have had them for 1 month so it is still early, but great impression so far.
My tank is 48x28x20 and I am running 4 units with 100* optics and the coverage is great. I have a mixed reef with a couple clams, and primarily SPS and LPS. I don't think I will ever put 70* or 40* on my tank, the 100* provide more than enough power for 20"depth.
There is no spotting effect from the LED's not blending.
I don't see any spot light, I do have 1 per foot so the lighting is pretty tight.
The colors look great, you can really play around to find the right color temp to make the corals pop.
Aside from having the new XML Leds, the 400-410nm Leds, modular, easy to change optics, I think its the nicest looking fixture out there, especially with the units angled at larger show pieces in the tank, it really stands out.
About the mounting, really plan well when you first set it up. Place the cables and the cable holders in the exact spot you want them before you link it all together. It is a bit akward, but looks good when its all finished.