UPDATE:
I tried the new packages, and it installed all except one package (librsvg2-common), breaking my system.
DO AT YOUR OWN RISK!
UPDATE 2:
Anyone else facing issue with the aforementioned package, following command allowed me to get my stable system back and install rest of 6-v3 packages.
sudo mv /usr/share/doc/librsvg2-common/changelog.Debian.gz /usr/share/doc/librsvg2-common/changelog.Debian.gz_BK


Phoronix did some benchmarks contrasting stock amd64 vs. amd64v3. Not really impressive right now, but who knows if things will improve later on
Do you know if a similar report exists for Intel based CPUs?