A train can easily move more than 960/s, but the train isn't always moving. To actually exceed 960/s over time with trains gets some massive stations.

And a track is two spaces, thus two belts can fit. Even just blue belts gives 1440/s for the same space.

Your first item delivers a lot faster with trains, and when you're dealing with stuff that spoils the faster transit is a big benefit, but for the most part I find trains underwhelming other than on Fulgora where you don't really have a choice.