GE just nerfed the rate of charge/discharge of my batteries...

The charge/discharge rate was 3600 watts pH, now it is barely over 2700 after the firmware upgrade... is this intentional?

Check the charge / discharge rates set on the web portal, inverter remote control. Firmware upgrades seem to reset a lot of the registers, but they don't update on screen until you click on the refresh icon for each of them. Hitting the 'read all unread registers' doesn't seem to do anything; you need to 'read' each of them individually (I've found). Then modify the settings as necessary...
HTH