I wouldn't call it a bad game, but it is definitely my least favourite game of the series, I only finished it because I wanted to see the story and refused to admit that I couldn't beat the game. But overall I agree with you, the vehicle handling is terrible, enemy patrols are a huge pain in the butt, if you accidentally hit them during a timed mission then you're pretty much fucked, and there are these long missions where if you die you'll have to start all the way from beginning.
Still, if you do have time I'd suggest you to give Jak 3 a try, it fixed almost all the problems that I had with Jak 2, the vehicle control is much better and the missions are quite interesting imo, it's actually my favourite game of the series even after the bad time I had with the second one.
