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Based on the measured thickness, you can reuse those rotors. Now, the other things to check:
Is there a ridge or lip at the outer circumference, that may cause noise?
What is the surface finish like - are they glossy, blue, showing heat spots, etc? Any cracks or lines?
What is the surface condition like - any grooves or other wear that may cause brake pad noise after installing new pads?
While it is perfectly possible to reuse rotors, many times I replace mine simply because I don't want the hassle of doing them again if I get any brake noise with new pads. I know I don't need to, but I do get better braking that way, and I don't consider the cost to be significant. After 70,000 miles, I would figure they don't owe me anything. You may be on the original rotors, or the second set, can't say.
If you do reuse them, bed the pads in, and then see if there is any noise (squealing, squeaking, rough noise on application, etc). If so, you may decide to replace them, or simply to live with it. If they are just fine, then no worries, you are good to go. You will be replacing them next time based on the thickness anyway.
Don't get them machined.
I would only use OE rotors. The ones I got last time had an anti-rust coating, and they performed well. The differences between good and cheap rotors are trueness, and the design of the cooling fins. Cheap rotors will have straight fins, less cooling, and are thus easier to fade. If you look at cheap ebay rotors and OE rotors you will see the difference. Many consider rotors to be simply a commodity, and buy the cheapest. I don't share that opinion.
I would never buy drilled or slotted rotors. They are purely for looks when parked, and have reduced performance (noise, structural integrity, pad life). The rotors that were designed to be drilled were cast that way, they weren't simply blanks drilled afterwards. I figure that brake parts that are at their best when the vehicle isn't moving aren't the best choice.
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2007 X3 3.0si, 6 MT, Premium, White
Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue
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