Verizon is offering a 2-for-1 offer for either the VX4600 or Sam SCH-a650. I prefer the LG largely because of its external display (Samsung lacks one). Aesthetics aside, I want to select the one with rock-steady performance and better overall coverage. Any advantages to Samsung being tri-mode vs. LG's dual mode? Would appreciate feedback on this distinction, even from those not familiar with the actual phones.