there are not any advantages to the new hboot(and some wierd quirks as hadron and i have found
),and if you want the new radio,id install all the firmware to match it,wich is a bit more complicated of an explnation,since flashing only "firmware.zip" from the OTA package is only changing what is different from 4.3.
flashing only the radio,or only the firmware.zip may end up with a mix and match combo the leaves performance worse than it was before with an older set of matching firmware.
we can go over some ways to update in either s on or s off scenario,but well need to know your current build/hboot and wether your s on or s off. for now,flashing the rom only will stop the OTA nags and get you the benefits of the new OS.