Real De Catorce, Mexico. Approach north or south ?

[Motzilla]

I will be going to Real de Catorce.riding a BMW GSA 1200 along with 3 friends. Our approach could be from the south, take toll free road north east from San Luis Potosi , go left (north) on a dirt road after "Charcas". From that point we would face arround 60 km of unpaved ground. The other choice would be coming from Matehuala (highway 57) making a left (east) at toll free road 62, and another left (south) after "Cedral" this last 30 km would be dirt road into Real de Catorce .

Bottom line: any one who has done either way has any advice on the dirt road conditions ? I know most people go into Real thru the shorter (north) approach. I was interested in doing the southern approach, but I am concerned about the conditions of this longer dirt road.

Thanks