Well I have used both so I'll just give ya a couple different pros and cons..
I'll start with the pros..
Micarta-Nice look, very unform and stable
G-10 - rugged hard working stuff
i like the look of the micarta, especially the linen types over the G10, I think it just looks more uniform.. Although the G10 is a tougher material.
Cons
Micarta- burns if it is worked too fast, or with worn abrasives, also the colors in some can bleed out if worked too hot..
G10- this stuff is like instaling fiberglass insulation in the nude! This stuff is mega nasty for your lungs, as is micarta.
G10- COLOR... I have found a wide varieties of colors in this stuff, from red to blue to green, and black, but the problem is consistancy in color, you can get a peice that looks blue and when ground turns teal, and you can get another peice from the same place and have it stay blue.. i have had the blacks sort of a grey color and the reds even a little yellow..
I dont beleive one is any better than the other, I think each has its own place in the market, and based upon usage and appearance, each has its own drawbacks..
Alan Folts..