Personally I don't like to update the firmware unless it is necessary. If my drone and ST10+ are working as it is supposed to I won't take any chances with the updates. I have had heard some horror stories about malfunctions right after updating the firmware on both the ST10+ and the drone.
Good advice from BF8 and HB707. As a PC Tech, these type of flash, EPROM updates should be used with caution. Always research the reasons for the update. Does it fix a problem....or does it add an additional language capability. The downside is that flashing an EPROM can have disastrous results if the power blinks or an erroneous error occurs. Your bird could, seriously, become a brick. I always wait....and read the forums and such, to see what the results of the update are. And then make my decision.