i say christmas because i was raised in a christian household, but if people say x-mas then i don't really mind since there's different religions and people and such. i don't think i've heard anyone say it verbally though...? i don't think i know anyone who says that, but when people get angry over companies using it it's kinda funny tbh
vocally i say christmas
in text, i use both to be honest. xmas more often as it is faster to type. but it also depends on what i am writing as well. so both really.