I'm using Hetzner services for several years so far (luckily only for personal stuff and friends minecraft server), and had this problem few times. Every time I said to myself "I will get away from Hetzner ASAP", but I always stay there. I would NEVER imagine to run a business hosted there at all, and here is why...
DDoS is a common problem many companies are facing, but Hetzner's policy on that is really crap.
If someone starts DDoS on your dedicated, after several minutes they just shut down your dedicated from network, and send you an email like "We disabled your network because you have DDoS attack on your server. Write us an email to reenable your network". And of course, several hours later I saw that email and tell them "Okay, please enable my network", but boom, I will have to wait Monday, because their support that can ACTIVATE network on a dedicated works only from Mondays to Fridays ...
And then the person who attacked me sends me anonymous email like "lol, I bought 5$ packet at [some random booter/network stresser website], and I have put you offline for few days for only 15 minutes of DDoS, HAHAHAHA"
So basically yea, start small flood from random VPS/dedicated or whatever that is 100mbit or more, leave it on for several minutes until Hetzners system automatically disable network from person you are attacking, and look at them being offline for few days :)
I'm ordering a new dedicated from someone else now, no more Hetzner...
You get great support (always had phone calls answered pretty much instantly and emails answered within a few minutes and all the techs I've dealt with knew what they were doing).
You can issue automated hardware resets and even get a remotely-controlled KVM attached to tweak the BIOS or regain access to your machine if you messed up the networking config (usually only takes a few minutes to get the KVM attached).
Orders for new hardware are also really fast - dealt with within the hour and often in under 15 minutes.
But there's no such thing as a free lunch. If you host at Hetnzer, you have to be aware of the reasons why they're so cheap, namely:
1) The servers are 100% unmanaged. They'll install new hardware for you if you ask them but everything else is up to you.
2) A lot of their hardware is desktop-grade, e.g. Intel Core i7 CPUs and non-ECC RAM. They do have some server-grade hardware in their high-end range however.
3) Their servers are in Germany. So you get quite a bit of latency if accessed from Asia or the West Coast of the US (see [2]).
4) They don't have any DDoS protection. In case of a DDoS, your server will get null-routed (but they tell you first). Again: 100% unmanaged. Up to you to deal with it. I've been lucky enough to not have to deal with a DDoS but my first port of call would probably be CloudFlare it it happened.
Provided that you're happy to do some sys admin, Hetzner is brilliant for a personal server, a CI server or even a prod server for a bootstrapped startup.
For literally next to nothing, you get a really powerful machine that will easily handle big traffic spikes without a breaking a sweat. And dedicated machine means that you get excellent and consistent CPU performance and disk I/O. If and when your startup takes off and you get funding, you can then choose between hiring a sys admin or moving to a more expensive host that offers a more managed setup.
[1] http://www.hetzner.de/en/hosting/produktmatrix/rootserver-pr...
[2] https://news.ycombinator.com/item?id=3898714