TPU didn't use any voltage tweaks. Others who have pushed more voltage have hit 1060 core
Do you have a link to those reviews that used voltage tweaking?
Guru3d is the home of Afterburner and they usually use voltage tweaking, but not on the GTX560 reviews. Without voltage tweaking, they got the vanilla GTX560 up to 980mhz and the Gigabyte SOC up to 1044mhz, again without voltage tweaking.
Minimialistically smart design by Asus? I think so, so under load the MSI stays 10 degrees colder and only a couple in idle. I remember the reviewers always sayiing the cooling design on the asus was great