"The Smokester"'s comparison of the Ortlieb and Lone Peak is right on the money. The only thing I'd comment on: in principle, I'm sure he's right that one should avoid putting heavy stuff in the front pocket of the Lone Peak. I think of that every time I ride with only the bar bag and I put all the heavy bike repair stuff (innertubes/tools) in that pocket. But as a practical matter, I've never noticed any difference in handling when I have that stuff in the front pocket versus in the main compartment.

To me, the Lone Peak's side mesh pockets are more useful than the map pocket on top, but I'm mainly using it for randonneuring so I have a cue sheet sitting on the stem and I'm not looking at a map. My friend who has the same Ortlieb puts his cue sheet in the map compartment, which is genuinely useful on the Ortlieb. But the Ortlieb mesh pockets are a joke. Just big enough for a single-serving pouch of Hammergel.