I like the room/capacity and multi pockets of the lone peak. But it's terrible in the rain. In a steady rain after 90 minutes of riding I had puddles in each compartment.
The banjo bros was nice in terms of waterproofness, but only had one compartment and I could not get that thing to stop moving down everytime I'd hit a bump. Even with the wire.
I was wondering about the Ortlieb or Arkel or Topeak. The Ortlieb being the most interesting.
I'm used to the permanent mounts, and thats not a problem for me.