Sorry but that is not true at all. Materials change.....and therefore so do their weight.
I have two Prodigy builds. One has a Asrock Z77E-ITX. One has an Asus P8Z77-I Deluxe. They are both equal but the Asrock has a MUCH faster boot speed regardless of SSD/HDD and a BIOS that is easily compared to the Asus BIOS. Sure the Asus has the weird DigiVRM Daughterboard for overclocking but the Asrock proves that you do not NEED that for a good overclock.....which to me is excellent quality as well.
Both are of the same quality.
It is about what SUITS YOUR NEEDS....nothing else. I would have bought ANOTHER Asrock Z77E-ITX for my second Prodigy but I got a great deal online for a slightly used Asus which was less than buying a second Asrock.