As an outsider I tried to look at this as objectively as possible.
This really isn't complicated. The two jobs are basically the same. pluses and minuses at both.
Can I win "here"
At Purdue, right now you have as good a shot as anybody to win the division in one of the top 3 toughest conferences in america. That's a big deal.
At UofL you are looking up at the entire division and you likely see as Clemson and FSU as teams you're going to struggle to beat.
I'd give the advantage to Purdue in this category.
"Where can I get talent"
I actually think both jobs are tough in this regard. At Purdue you're fighting Notre Dame and IU for recruits in state. Chicago, while a huge metro doesn't have a ton of talent.
At UofL you are in a state that doesn't produce much talent and you are in a city that doesn't produce much either. Since UofL joined a major conferrer they have won with players from Florida. Brohm has to ask himself if he can get the level of guys he needs to get to have a chance to beat Clemson and FSU. Since Jeff is from Louisville he doesn't really have another natural "recruiting base" other than Louisville.
But at Purdue he has a natrual recruiting base in KY and has his own backyard to compete in to. This is something I don't think many folks are looking at.
This is how stoops has won at UK. He has a natural recruiting base outside of kentucky. It's how Strong won at UofL. he had strong florida ties.
Advantage - wash/purdue...
But that the end of the day the question is this... Does Jeff want to go home. Is it really his "dream" job? And is the time right?
Let's assume his family wants to go/is willing to go.
If I was jeff I'd ask myself one question. "Am i willing to put myself in a position to have to tell UofL goodbye if one of the top 10 jobs in the country comes open? That's the part that nobody knows the answer to. If he doesn't care about ever coaching at USC, Texas, FSU, Notre Dame etc... Then he will leave and "come home". But if he has his eyes on a "huge" job then he probably delays that by 5-10 years. The rebuild at uofL is going to be MUCH MUCH MUCH harder and longer than the Purdue rebuild. Don't be fooled. Jeff brohm inherited a much better roster at Purude who had just won 13 games the previous two years. He had a qb and depth. At UofL he inherits an undisciplined and bad roster with limited options at qb. An offensive line that loses 3 starters off of the worst unit in major college football. he inherits the worst UofL defense in history.
That's what makes this so simple. For anybody other than Jeff Brohm, there is no way in hell they leave purdue. So the question is. Is this truly his dream?