Hi Brian,

I think it depends on your use case. If you are an Industry
Professional people go with ZBrush. If you are a hobbyist
people go with 3DCoat.

I have both and I love Zbrush much much more than 3DCoat.

The brushes in ZBrush are more fluid and ZBrush can handle
on small machines much more geo than 3DCoat.

The only thing were 3DCoat is better is in it's
PBR painting tool set and image to mesh functionallity.

And last but not least, 3DCoat is in permanent beta state ...
So always little bugs which will be fixed in the next beta and
so on.

Regards
Stefan