Since owning my Droid Razr Maxx HD, for me the signal has been pretty solid. I had both this phone and my old HTC Rezound phone side by side reading the dBm and they were pretty much identical in both voice and data. The only radio issue I had w/ my Rezound phone was the 3G would randomly drop out and the only way to restore it was by rebooting (4G was solid). Luckily I have not had any data connectivity issues with the Razr Maxx HD.
Now if you were to compare the radios in a HTC & Motorola smartphone against Samsung... You'd know right away. The radios Samsung use for their smartphones SUCK. I've compared the SG3 Verizon model to my Rezound and Razr HD Maxx, I find all Samsung smartphones (not just Verizon models) in general to consistently have -30dBm (higher is bad) than the other two devices for both voice & data.... Not only that, but running speed test comparisons, I found the speedtests results were 30% slower vs HTC or Motorola when running tests via 3G/LTE & wifi.