I think the main difference is pretty simple. Pitino put emphasis on basketball players that could make plays and shoot and utilized their skill set.The great irony between the Calipari Era and the Pitino Era is in my opinion, chiefly found in Calipari's abysmal seasonal failure to land elite playmaking forwards. The list of his successes - MKG, Knox, Keldon Johnson, Jones - pales in comparison with his failures: Ingram, Zion, Reddish, Stan Johnson, Wiggins, Oubre, Barrett, Jalen Johnson, Brown, Barton, Tobias Harris, Porter Jr., Bridges, Tatum, Isaac, Parker, etc.
In contrast with Pitino, Rick's best teams featured elite playmaking wing/combo forwards who could pass, shoot, slash, and handle the ball - guys like Mashburn, Walker, Mercer. T-Mac was enticed by this and was going to pick UK before Adidas paid his coach off to lure him away from Kentucky (Fact). Yarbrough was on the way (and he was the top small forward and maybe even the top player in the class of 1998).
Pitino also went to the Final Four each time his team's best player was an elite playmaking forward (1993 with Mashburn; 1996 with Walker; and 1997 with Mercer). It seems that Pitino built on his brand with these players by continuously pointing guys like T-Mac, Rhodes and Mercer at his previous success with Mashburn. Yarbrough loved UK because of what Pitino did with his high school idol, Ron Mercer. Pitino used this to his advantage, but Cal has never had success with an elite wing forward to the extent that these kids see his work within the context of allowing them to be all-around players. MKG was a workhorse - the type of player that guys like Tatum and Brown won't pattern themselves after - and Knox is irrelevant in the NBA, and thereby useless on the recruiting front.
This contrast has always bothered me because I still feel that some of Kentucky's better non-title teams were an elite forward away from being incredible. The 2017 Fox/Monk team (Bridges or Tatum) and 2015 38-1 team's (Stanley Johnson would have been enormous) were notable examples. Even the 2016 with Ulis and Murray probably advances with Jaylen Brown on the roster. Put Reddish on the 2019 team and we win the title.
This next class will once again test Cal's ability to land his first true elite wing forward since MKG. Chris Livingston and Brandon Miller are both on UK's radar. Calipari has yet to prove that he is capable at landing an elite wing forward more than once every half-decade.
Will that trend begin to change now? Is there any truth in players assessing programs based on previous success with their positions? Are wing forwards scared away by Cal's approach with previous elite wing forwards (Knox, MKG, Whitney, Juzang) and their lack of success in the NBA (MKG/Knox), or in the case of Juzang, Whitney - their lack of success under Calipari?
Cal put emphasis on athletes that have huge potential draft status.