If you do any substantial overclock, meaning you are going to do a little bit of over voltage, the presence or lack of XFR matters little, and you are definitel

If you do any substantial overclock, meaning you are going to do a little bit of over voltage, the presence or lack of XFR matters little, and you are definitely going to go above turbo core freqs. XFR is going to be a nice-to-have unconditionally because of it being on the fly adjustments, but it does not seem to be a feature that it is going to make you buy an X version over non-X. It seems to me it will come down to the classic spend less risk more, spend more risk less in terms of overclock, just like it was for vishera 8320/8350/9370/9590 , so I don't expect many features differences between the versions.