i have both the model 1 (which is hte same as the model 3)and the pro, they both work awesomely, the pro is a little more accurate as there are more teeth on the encoder wheel, it also weighs a little mor eso its spins nice, the model one works great too though. i also have one plateless and one with a moutning plate, both ar eeasy to to do and look nice.
so sorry this probably doesnt help you make your desiscion, but gives you some info on both, i bought my pro first, then my model one.