In order to have spares and to make changing cassettes a snap, I bought a second set of wheels - same as the first. But of course it's never that simple. When I swap the rear wheel the rim in relation to the brakes is offset a bit to one side and I have to adjust the brakes to get them square again. It's not bad - maybe 1/8 to 3/16" difference. (Front is pretty square.)
Other than the annoyance factor, is this an issue? What would I have to do to even them up?