Hetzner's biggest problem is that they can and do terminate a user's account without warning if the user starts using CPU resources very heavily or for any reason. This is for very legal usage, of course. This can and does happen to people in months. When this happens, consider your data lost and your account blocked. They will offer no explanation whatsoever, and will even send you a bill for the full month. Hetzner simply cannot be trusted, not even a little bit.

As for OVH, they don't do the above, but they have week-long unplanned downtimes, so using them is okay only as an optional resource.

Even so, there are lots of providers that are cheaper than Amazon and won't screw you over.