As David stated it depends on your paper and what you are pleased with. The one thing that I might add is that the noticeable difference between a grade two and grade three paper is the severity of the slope on the characteristic curve of the paper. Therefore a typical grade three paper when compared to a typical grade two paper will have a more severe slope in order to compensate for the lower contrast of the negative. This leads to a certain degree of compression of the tonal scale of the negative.

I would agree with David insofar as targeting to a grade two paper for all sheet film users. The one exception that I make from this is in the use of 35 mm film. There I would target my negative contrast for a grade three paper for the reason of less grain.