I did the 2-wheelset thing, but not with disk brakes. Cx tires for off-road and cx races...road tires with lighter wheels for the road. Get a 2nd cassette, and in your case, the exact same disk rotor, and your golden...might be more tricky with disk brakes to make sure the brakes line up right. For me, I can switch wheels without making any derrailer or brake adjustments.