Comparing with ddos protection, OVH would win here, but comparing to price and configuration Hetzner would win. Hetzner has ddos protection too, but OVH's one is better, especially their game protection for game servers. Hetzner has total 6TBps network capacity, while OVH has 17TBps network capacity of course for both are global capacity.
If you are choosing only between the two, OVH wins in Terms of Protection indeed.
Hetzner protection is weak. Had some of their customers complain already saying it dont work and switching to us because we Provide Corero SmartWalls aswell.
Hetzner protection seems very basic.
OVH Protection i used 5 years back and it is indeed great. If not even better then Voxility. Because Voxility we used over transit aswell, they are fully dropping/blocking UDP in Always ON mode which is bad for UDP Applications like Voice/Game Servers.