I'm currently torn between the Pilot Acroball and the Zebra Blen. I'd love to hear your recommendation!

I want a ballpoint pen that

  1. is smooth, not scratchy on paper

  2. does not skip

  3. requires less pressure to write with

  4. can be used in long writing sessions

So which pen should I go for? Pilot Acroball or Zebra Blen?