Ortliebs look great and I know some folks who do serious touring with 'em. I'd get 'em too if I was touring.

But I still think the open top grocery panniers are the bee's knees for grocery shopping and daily errands. They fold up flat when not in use. The only time I notice them is with a really stiff side wind, which I've encountered only on some rural prairie highway hilltops. The empty weight is hardly noticeable considering my suspension fork hybrid already weighs nearly 35 lbs with the rear rack and heavy duty puncture resistant tires (1,110 gr each).

Tonight I fetched three paper sacks of groceries and rode home in rain. Each standard grocery paper sack fits perfectly in the open top panniers (Braums, Whole Foods and a few others still use 'em). Drop a sack in each pannier. The third sack goes on top of the rack. Spread a plastic trash bag over the whole mess (I usually keep an empty trash bag in the pannier). Bungee it down. Rode 7 miles home in the rain, hardly a drop touched the paper sacks. The wheel-facing surfaces of the panniers will be messy, but there's no rush to clean up because I'm not taking the panniers into the store.

And in dry weather it couldn't be quicker to use 'em. Just drop the grocery bags in and lift 'em out.

The grocery panniers cost a fraction of the price of Ortliebs. I can only speak for the Nashbar Townies but they're very well made, especially for $25 each. Most of the comparable open top panniers cost more, sometimes double that price.

Wire baskets would be more practical and probably more durable over the long run. If I had room for a dedicated errand bike that's what I'd get.