On the PS2, I never actually got very close to finishing it, I only played like half the game
But since then, I bought the HD collection on PS3 and then got it for free on Vita. I've now gone through and platinumed both with 101 power cells
I played Jak II again on PS3, but never bothered to get all the precusor eggs for my platinum and I've just started Jak 3 HD on the Vita
I did actually find Jak a little frustrating by the end with loads of cheap 1 hit kills, but all 3 games were fantastic (even if Uncharted 2 was better)