I actually did enjoy Killzone 2 more than Halo 4, no stanning.
Killzone 2's campaign was highly memorable to me, Halo 4's campaign was good but not great to me.
I also got hooked on Killzone 2's MP and it was kind've underrated. Even made top 6% in the world on it.
Halo 4's MP I never got into. Not saying it's def better, I'm sure people feel otherwise but I would play Killzone 2 again before Halo 4.
Legit no stanning either. At that time I had beaten like 4 PS4 games and was basically 360 only. shyt my XBox Live gamerscore like 18,000 over a 2 year span compared to barely anything on PS3, I legit just like it better, don't wanna be called a stan.
I will say though Halo 2 MP>>>>>>pretty much everything else