The M8N >reports< higher satellites and thus lower P/HDOP, means nowt, the logic putting the satellites together is within the ublox and 3DR's testing found an M8N in practice in a Solo offered in reality little benefit, issues cited included its susceptibility to noise.
I've seen this mentioned before about the M8N. My reality so far has differed from that reality and I have yet to hear of anyone else having problems with the M8N.
If I experience problems I'll certainly post about it. I hope others would too.