Dug up some good info myself, had been searching for some time, then of course found it on my own after asking the question...
Charge is using a VIA Telecom CBP7.1 CDMA modem instead of the old Qualcomm QSC6085 in the Fascinate
LTE modem looks to be a native Samsung designed chip called the CMC220.
Knowing that it becomes more clear how the performance and battery life can be substantially different (better?) than the Thunderbolt's MDM9600/MSM8655 combination.
Reference:
Samsung DROID Charge