So I tried to add all of the Data Tweaks in the first post, and lost all connectivity (RevertedASOP rom which is AOSP/CM7 based). Had to re-flash a backup to get connection back. Then just edited the following existing lines without adding the new ones. Connectivity was not lost, so we'll test and see if this improves anything.
ro.ril.hsxpa=3 (was already there)
ro.ril.gprsclass=12 (was already there)
ro.ril.enable.dtm=1 (was 0)
ro.ril.hsdpa.category=28 (was 10)
ro.ril.enable.3g.prefix=1 (was 0)
ro.ril.hsupa.category=9 (was 6)
wifi.supplicant_scan_interval=150 (was 200)