There is still one bug:
Please look at the screenshots to understand

When you place two hoppers vertical and now power the hopper below...
-it should not get items from the hopper above
-BUT it gets the items, and this is a bug, which was the hole time and is still not fixed

Mojang and Jeb pls hurry up

This bug is ONLY at hoppers, not at chests!

And another bug, I think Jeb said, that a comparator can read out data from chest in minecart too, but it doesn't work.