(adsbygoogle = window.adsbygoogle || []).push({}); I'm currently on OFW 4.25. I'm seriously thinking about downgrading to 3.55. If I do, will I lose any data when I do a data transfer from my 3.55 to my 4.25?

not exactly sure what you're asking...
you will lose everything that is on your 4.25 console. everything from your 3.55 will be written to it. the 4.25 console will be an exact facsimile of the 3.55. apart from the firmware and some settings of course. all game data etc. will be overwritten on the 4.25.