If the wear on the pads is uniform then I would say there is no problem using them with new rotors, in fact I just did that on my 240D. It may take a couple of hundred miles for the rotors and pads to "mate" completely, or to let the minor surface irregularities in the pads wear. But even new pads need to break in so this is nothing special in the case of reusing them.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz