Tusk's products are hit-and-miss. It may be fine, or it could eat up brake pads in a single ride, and end up warped the first time it gets heated up. For what it costs to get a known good quality rotor, i wouldn't take a chance on it. When my stock one got all chewed up I got a Vesrah rear rotor with drilled vents for $70. I don't think that's much more than the tusk costs, and vesrah's stuff is always good.
i agree with you on the tusk products. some things you can get by saving a few bucks and others can cost you more because of the fact that now you have to replace the tusk part that was bought to replace what was originally wrong. i hope that the rotors you bought are one of the good items they make. let us know how they turn out.
Here are the pics. The stock rotor DESTROYED and I mean destroyed my EBC pads so I'm swapped back in the stock pads which weren't that bad anyway. The only problem I ran into while installing it was the allen bolts on the rotor. It was the first time I had to use heat to remove any of the hardware on this bike. Here are the pics I promised.