I don't know about the Nokia, but I do know that my 9900 has better reception than my Moto V710. It also has better reception than my wife's LG 4500, but I think that's only because her's is digital only while the 9900 is Tri Mode.
Since both phones I take it are picking up CDMA on Cellular (800 MHz)?
Being a Tri-Mode or Dual Band won't make a difference unless it is a weak digital signal and the tri-mode goes into analog. That is where a Tri-Mode has an advantage something in the Dakotas and Wyoming is a good thing to have.
It is how much power (watts) and how good the annenta and transmitter are.
max wattage on CDMA is .01 watts
max wattage on AMPS is .6 watts