5 felt like a good length to me while 0 felt too short for some reason. I also thought that most of the missions in 5 were downright perfect. Not to mention completely battrout insane half the time. It's really hard to top things like destroying massive submarines with doomsday weapons, threading the needle between radar detection ranges, and shooting down a space station with a doomsday laser of it's own. Compared to how balls to the wall 5 was, a lot of the missions in 0 felt a bit underwhelming. But every time you thought 5 couldn't possibly top a mission it would turn around and prove you wrong.