I've gotten very similar front rotors, and I think from the same ebay seller. The fronts look like your rear rotor. I was postponing my reveiw until I get more miles.
After a few rides, they were pulsating, and I was puzzled. So, I got a dial gauge and a micrometer, and spent a couple of hour measuring the runout and the thickness.
The thickness was dead on 4.90mm everywhere pretty consistently. The runout on one of the rotors was very small - within +/- .02mm. However, on the other one it was +0.12mm to the outside. It is still within the spec of +/- 0.3mm.
Then, I searched our SH.ORG on breaking in pads and rotors, and followed an advice in
post #3 of this DIY sticky thread
I actually did three sets of runs instead of one - at 60 mph, at 70 mph, and at 80 mph. Each of them for 0.5 - 0.7 miles. Prior to this run, I also sanded the brake pads with 100 grit paper (recommended by EBC Tech). Holy cow! What a diffference! Now, there is almost no vibration. The pad materials is almost evenly spread along the rotor surfaces. About 10-15 sec into each run I feel like the brake lever is being pushed out - I am guesssing due to the heat expansion.
It is so true about gradually heating up the rotors and gradually cooling them down as explained in the thread I mentioned. During my first rides, I didn't and I am guessing that's why one of the rotors developed a runout.
I also noticed they cool down a lot quicker than stockers.
On the side note, anyone who uses slotted rotors has to keep in mind that they are a lot more likely to produce high frequency vibration (not shakes) if caliper pistons produce uneven pressure, i.e. if you didn't rebuild your calipers for a few years, I can almost guarantee that the pistons produce uneven pressure because some pistons are binding more than others.
Here is why. All slotted rotors are CAD designed so that the entire brake pad has the same contact area with the rotor no matter what the position of the rotor is. Another words, as the pad goes over a slot, the other part of the pad finishes going over another slot. That is why the brake pads apply the same braking power as the rotor moves. However, if one part of the pad squeezes the rotor more than the other part of the pad, as this pad goes over a solid metal this creates more braking power, and as this part of the pad goes over a slot, this reduces the braking power. This creates a very high frequency pulsation which may be perceived as the noise.