US05 is a fairly old firmware. US0J will provide you with bitsetting support and also a greater range of supported media types.
However, if you don't need bitsetting and if your drive is working just fine as-is, there is really no reason to upgrade to US0J (you know the saying, if it ain't broke...)
*Edit: to comment on the areas that you pointed out in the screenshot...
1/ if you do upgrade, the process is fairly painless and does not require DOS
2/ you CAN revert back to an older firmware if you want (despite what the website says)