Pac 12 is the most up for grabs conference. There is no consistent power structure and pecking order in terms of alpha dogs dominating for long periods of time.
I think the talent out there is more fluid in their brand loyalty compared to Big 10, SEC, and ACC regions. Florida, LSU, Miami, Michigan, OSU, and FSU, etc can have down periods but they will still stock their rosters with more talent than UK, Wake Forest, Purdue, IU, BC and Vandy could ever hope to have in great times.
Pac 12 has become a very finesse/offensive oriented conference. Meaning you don't have to go build a program that is strong in all 3 phases of the game from top to bottom. If you have an O than can win a shootout you don't have to worry too much about D, ST. Leach doesn't have to worry about the fact that USC, UCLA, Stanford, all probably have better athletes overall and bigger better linemen, because his offense is a well oiled machine.
It's a very good conference for coaches because you can go to any program and become competitive in short order. Kelly, Harbaugh, Leach, Petersen. All "system" guys whose programs have distinct identities. All take over programs that were not traditionally competitive and turn them into players in the conference at least, if not nationally as well. Look at Kyle Whittingham, been at Utah for a while but relatively new to the Pac 12 and is establishing the Utes as a strong competitive program in the conference.