For me, micarta has a better feel in the hand, but tends to look dull at first. G10 looks great, with sharper colors and pattern definition, but feels cold somehow, and doesn't improve with use to the degree that micarta does. Micarta gets better and better looking the more you use it and mess around with it. Both are nice. I tend to lean towards micarta as being nicer. It seems to be more an organic material, if that makes sense, even though it is mostly synthetic.
I do prefer linen micarta over canvas, though. And if paper were still available, I bet I would really, really like that.