Here's every Bears QB drafted since I've been a fan compared to Justin Fields.
Jim McMahon: Weaker arm, slower, durability issues. Excelled in reading defenses though.
Mark Casale: Meh
Jim Harbaugh: Mobile, but slower and much weaker arm. Never had the stats of Justin Fields in college.
Brent Snyder: Who?
PT Willis: Meh
Paul Justin: Meh
Will Furrer: Ran hard, but meh.
Moses Moreno: Meh
Cade McNown: Had great numbers in college, but a headcase. Weaker arm, less mobility, terrible accuracy.
Rex Grossman: Decent college career, not a consensus top QB. Lacked size, and mobility.
Craig Krenzel: Please...
Kyle Orton: Weaker arm, much less mobility. Heisman hopeful before injury. Not bad career for 4th round QB.
Dan LeFevour: Nope
Nathan Enderle: Nope
David Fales: Meh
Mitchell Trubisky: Less experience and success in college. Less accurate, slower and smaller.
That list is why folks are more excited about Justin Fields than any QB drafted by the Bears.