The Millennium Teeth do make a difference, insofar as they were digitally scanned from a plaster cast of real teeth, whereas V/S/M's choppers are essentially nearly identical Chiclets by comparison. The only trouble with them is that because they're parented to your figure's eyeballs, they sometimes pop through lips because P4 doesn't have collision detection to know when the lips are moving inward. DAZ seems to be aware of this, because often after changing head position or the camera position, the teeth adjust their position to hide better. As far as decent smiles go, I can't add much to the above. Try experimenting with the A phoneme dial as the basis for a smile and then closing the mouth THEN gently adding smile and negative value frowns.