Hi Alex,
PE2 has a control knob for cast control, and the PE3 does not.
PE2 has 5.3:1 ratio, PE3 has 4.5:1
PE2 has a max drag of 45lbs, PE3 has 50lbs.
PE2 holds 320m of PE3 line or 400m of PE2, PE3 holds 400m of PE3 line.
PE2 has a ball knob and the PE3 has the classic JM T-Bar
Benny