As far the M8, it seems no better or 1 to 2 dBm points weaker than the S4. We also have a 5s and DNA to compare with. In order of reception:
DNA
5s
S4/M8
My family's comparison suggests the M8 is not a great device for radio reception on the Verizon network in the areas we live. The wifi also seems weaker on the M8. Too much metal?
The one phone we have not tested yet is the S5, so as per the topic, does it have better reception than previous Samsung models to the S4? I am not juggling anymore phones and my son
is an HTC fan. Loves the DNA and the M8.