Do larger blade widths (6/8 or larger) strictly work better on heavy beards or do they also work better on coarse beards? My beard is not exceptionally heavy, but I have been told by my barber, who has given me a shave once, that it is pretty coarse. Therefore, do larger blades improve the quality of a shave for coarse, but not necessarily heavy beards? Or is the quality only improved with a very keen blade of any razor -- like a 5/8 or even maybe a 4/8 razor?

Thanks,
Rob