havent upgraded my iphone since i first unlocked it due to the effort of doing it then and the 10s of trys to get it to work

my iphone is coming to the end of its life, [microphone doesnt work properly] so was wondering if its worth upgrading it or is the risk of ruining it [corrupted ancient baseband and unsure of how to rectify it] is worth it
also battery lie is poor and i hear higher firmware is more of a drain?

this will be my last iphone because of the poor improvements to the new version but i need this to last a while longer before something like the satio comes out,

so is it worth the risk?