In a blockbuster opening salvo to the 2017 trading season, the Cubs landed one of the best gettable arms for this cycle.
First, let's talk about what we've lost. Eloy Jimenez is a hell of a prospect (No. 5 in BA's midseason ranking). He has light-tower power, though it hasn't translated onto the field at quite the same rate. He's still very young with a few years of seasoning left in the minors, and he has as good a shot as anyone currently in the minors to be a .300/.400/.500 guy. He's a nice fit in the AL, as well, as he could easily be a DH when it's all said and done.
Dylan Cease was sort of my pet prospect, with a 98 MPH fastball that he can throw for strikes and a curveball that wipes hitters out. He has the same injury problems that most hard throwers have, but he could quickly become a frontline starter for the White Sox.
That said, Jose Quintana is already one of those. After a rough start to the year, Quintana has been what he's always been, and that's an extremely efficient and good starter. Over the past 3.5 years, Lester and Quintana have identical fWAR (16.6, good for 7th in MLB). Quintana isn't an overpowering pitcher, but he locates the ball extremely well and is very consistent. The only worry is that he isn't as grounder-dominant as a traditional frontline guy is (so a juiced ball might adversely affect him).
Quintana is under team control until 2021, so this is as much a play for 2018 as it is for 2017. It swings the pendulum away from "sell" to "hold," mostly because the Cubs simply don't have tradeable assets in the minors anymore. Still, I really like this trade (more for next year than this one), and I imagine that White Sox fans should like it too.