I have experience only with Hetzner They are a pretty good company but everything is basically bare metal, meaning you need to be able to support everything yourself. Pricing is really good, but that is because of what I mentioned above, not a lot of support. Can't say anything about Online.net but they look to be very similar.
There both really good to be brutally honest I love that Hetzner just released some DDoS protection and they have some pretty hefty servers. I've heard the most about Hetzner so id say go with review wise.
They both are Good in Dedicated Servers,But From my personal i can recommend OVH Because they Offer 256 IP's for Free You just want to pay at the first time when you are purchasing ! On this case i recommend OVH.
I have not used hosting from Online.net yet but tried a dedicated server from Hetzner (32GB of RAM, 8CPUs) its loading speed was average and it needs be improved and optimized more before I saw my websites load faster.
Hi energizedit, You're right about Hetzner Online's dedicated root servers being bare metal. You need to know what you are doing if you purchase one of those or one of our virtual servers. However, we do also offer a range of web hosting packages and managed servers. --Katie, Marketing, Hetzner Online
I am suggest you hetzner there always good quality 1 gbps port speed, good support and very cheap prices on powerful dedicated servers and they have Online Server Auction where you can buy dedicated server without setup fee and with big discount.