Pleased to see you are getting such nice results with your Winchester processor - I have the identical model in my new rig, with a Zalman AlCu and am presently showing around 53oC under 95% folding load.
However I have to say sometimes this has risen to 64oC or even higher and I am mystified as to why (this can even occur first thing on booting system after about five minutes of load). The only idea I have presently is that it might be to do with heavy memory access if the controllers are on the CPU now?
I am not sure how to tell if I have JVC motors or not - but I have identical spinpoint to you and am pretty happy with it. Then again I also have a Seagate SATA and a Barracuda ATA alongwith it, so that could be a factor
Do keep me posted if you experience any temperature anomalies. Also my idle temps never seem to go as low as yours (maybe your case is cooler? - my case temp is showing around 22oC prsently if the readout is to be believed, though I suspect 34oC may be nearer truth).
Do you use native ASUS utility for temperature readout? I am using MBM but had to add some compensation values to get it to match up with BIOS reports.