Well, I'll add something in support of the Arkel panniers. Their extra pockets, their detachable walkabout pack, and their simple but unshakeable mounting hardware all shine.

The tent pole/thermarest pocket on their GT panniers is the best. There's a fuel bottle pocket on the bag on the other side. These might be my favorite bike accessories by themselves. Other extra pockets for stuff you need right away-- like extra batteries, reflective vest, whatever-- make unpacking much more efficient. It's also possible to pull this stuff out of small top pockets in the front bag while riding.

The hardware is ingeniously simple. Nothing to mount on the racks but the bags. When they're locked on they are _not_ coming off. But when you're at the campsite you make a simple twist of the lock and off they come.

The Arkel bags are extraordinarily useful in regular operation. The single black hole of the Ortleib panniers, by contrast, would drive me crazy.

I've got rain covers with a grommet to permit draining, and I've never had anything in the bags get wet yet. For an extended ride in a downpour I'd use plastic bags in the interior.

It is true that for serious waterproofing, the Orteib bags are unbeatable. If that's a top priority then Ortleib are the bags to get.

From where I sit, though, it just doesn't rain that hard all that much during times I have to be out on the road. It's not worth sacrificing the other conveniences and advantages of the Arkel bags.

But lest a gear war break out, let me say that either bag is top rate and it would be far from a mistake to get either one. Enjoy using whatever you choose.