Just throwing it out there....In the past, the 'X' stamp has been notoriously piperazine based. Do a search on PillReports. Does this logo match the previous X pills? If so, I'd avoid!
[UPDATE - Now I'm a purist at heart, but for what it is worth, some friends of mine who are quite tolerating of the piperazine comedown said they (the old X Pills) were a strong and enjoyable high...notwithstanding the death like comedown that followed]