Sadler was an assistant to Gillespie in El Paso when that program helped both their careers take off. IMO, Sadler rode the wave of momentum that BG built, and has never shown me he can be a great great coach.
I believe his two years at UTEP involved an NCAA trip (1st year following BG), then an NIT the following. Barbee replaced him and inherited a program some in El Paso think Sadler did not help (trying to put it mildly).
I do think what he did at Nebraska is commendable, but he also (does this sound familiar?) never won an NCAA tourney game.
Personally, I'm not a big fan of what he looks like on the sideline: seems overly stressed, yells at players. There is something to be said about holding players accountable; I think Aston is a good example of that. But Doc took it to another level. There were mumblings in EP that the players did not like him.
IMO, an okay coach but not on the top of my wishlist. Also, his style of play is not compatible with the current roster.