I also prefer GB contents to OK. To me it has more interesting products, like the SPF setting spray (like the idea of a spf that I can put over makeup), the deodorant balm, the read diffuser, plus things that I’ve tried before and like, like the EH cleansing balm, and the iconic London mascara which is the only one I’ve used which doesn’t smudge.
OK has too many DoDs for me - eyelashes, eyepatches, Espa, setting powder, AA oil (it’s nice but I have stacks of them!), orange lipstick, brow product, highlight stick, 2 nail polishes, sheet mask - none of these things appeal to me.
As you say, it’s down to personal preference though, and it really depends on what you’re looking for a calendar.