I wonder if the 5200's CnQ profile is really all that developed? Some of the older AMD chips didn't have it at all, and the 5000 series is fairly old in CPU terms.
I just checked at CPU World, and the 5200 does have CnQ, but the Vcore range is pretty small 1.3 to 1.35 for one of the Brisbane cores, and it's pretty typical of the others. If CnQ is going to work on that one, the variance is only about 50 mV, assuming it doesn't go below the minimum. I would think that on the 5200, it probably only lowers the multiplier. That would be my guess, anyway.
The newer generation stuff, like Athlon II's and Phenom II's, are quite aggressive in power consumption, depending on the motherboard. My Foxconn doesn't really lower the voltage as much as I'd like, and it likes to overvolt, too, but it does do the job.