I wouldn't roll back if you have a newer build, and in some cases, the television will not allow you to roll back.
I don't know what happened with the firmware. Unfortunately, I can only speak on U.S. models and service. The best I can suggest is to call the Samsung customer service center in your region to inquire further. If the TV is working fine with the firmware, then there's no need to upgrade (and especially, in most cases, downgrade).
The other day i check for firmware updates for my LE55B650T2WXXC
and there was a new file T-CHL7DEUC-3001.1 , this was bigger than normal 40mb it was 80mb , i installed and all went fine . Then yesterday i noticed a new firmware again , but this time T-CHL7DEUC-3000.2 (looks older) and the firmware is back down to 42 mb , so anyway i downloaded and went to install , but this won't install , it says no file found ...
Is this because the firmware is older ???
Can you roll back firmwares ??