Get your facts right, oe-c is a version of 3.03 oe. There's 3.03 oe-a, oe-b, and oe-c Some people still like 3.03 oe because it is best for customization and idk what else, I'm using 3.30 oe-a and have custom topmenu still.
lmao since when has "oe" ment offical firmware,:0P i used to use 3.03 oe-c but why bother when you can use 3.30/3.40 oe which has better game compatabilty.
you decide if you want to upgrade or not,i just prefer to keep upto date with them. as for how to upgrade you should find all the help you need with a quick google,or even on here.