I don't own either phone, but I did have the opportunity to handle a Z10 and play with it. I'd thought about buying one as a potential upgrade from my N9, too. I didn't really care for it. The build quality seemed solid, but the thing has massive bezels around the screen and it's unnecessarily tall. I didn't like the way it felt in my hand, but it's nothing you couldn't adjust to. The software was really responsive from what I remember, but it's a lot different from Harmattan. BB10 is based around swipe gestures too (of course), but the whole experience is a lot different. Harmattan is friendly, slick and stylized. BB10 is clean, professional and functional. For me, the Z10 was just too bland. Totally functional, very smooth and certainly capable, but not for me.