To help (not really, as it turns out) with the diagnostic: my TAB (GT-P7500D) on ICS OTA is just as good as it was on the original HC 3.1. (In fact mostly nearly as good / often better than 5 other devices I run, alternating on two WIFI, here. (And BTW, HSPA+ remains "right on the numbers.") 0
Full disclosure: I did a factory reset for the OTA.