The 15mm AP and 8mm AP both are my all time fav mops. Both are equally amazing and honestly have nothing negative to say about them. I have several of these and always keep extra nibs on stock. This mop becoming popular in my city also, several of my friends carries these daily like me.
Recently found one of these laying around in the drawer of markers and started using it, and man, what a great marker. the black is super nice, smooth, good coverage. I have no idea when I got it, but it's definitely been awhile and it still works great. highly recommend.