I keep the second one in the garage so that I'll have it when the first one wears out. I don't put enough weight into them to cause wear, but just being on the bike while it rattles and such eventually causes wear.
I have a waterproof pannier on the right and a Wald folding basket on the left. The basket is great for when I pick up heavy stuff.
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Work: the 8 hours that separates bike rides.