Tressel was one of a kind, there is only one, and we will never experience that kind of run again. Heacock took over a great program and it quickly became just average; 1 playoff berth in nine years, and 0-9 vs Northern Iowa.
Wolford, although the style much different that Heacock, was the same. No playoffs, and couldn't win in November.
The grade on Pelini is incomplete. I would grade him a C- at Nebraska. No BCS bowl appearances, and several awful blowout losses. I don't want to hear about the 9 wins a year, a monkey at Nebraska should win 7 games playing Northwestern, Indiana, Illinois, and Rutgers every year, and throw in a couple of stiffs like McNeese State prior to league play. This past year Nebraska barely beat McNeese, and also played Fresno State and Florida Atlantic in the preseason.
Also, short temper and unprofessional behavior is not a positive, even though some on this board think that kind of behavior is acceptable.