Jet2 seating arrangements?

Hi guys,
flying Jet2 tomorrow, just wondering is the seating allocation like say bmi or BA where you get a seat number, or like EZY or RYR where its the ones that turn up eariler get the better seat?
Train times are a bit patchy, so wondering shall i turn up 3 and a half hours spending time on Level 13 T1? or turn up 2hrs and endure a shorter wait for departure?
Silly Question :diablo: