I can easily thread (usually) a #10 needle, #11 is still (usually) manageable.
Those #12 betweens go through most fabrics so easily - but I have a hard time threading them.
I also use either - sometimes it's which one I find first - other times, it's whichever one I can get threaded!
I'm not a 'real' handquilter - so don't take what I say overly seriously. When I took a class, the instructor recommended the #11 James betweens. They did work well.