The support replies really quickly, is friendly and efficient; the control panel is simple and doesn't sucks; their prices are quite cheap; they are forwarding abuses instead of shutting down your machine first and asking questions later (like OVH), and this is what they say about Tor:
While we embrace Tor itself, do please note that we do not condone any illegal activities it is used for, because we as (technically an) ISP will be held responsible for it.
Cherry on the top, only a few relays are running on their AS.
The only drawback is that the traffic is limited to several terabytes per months, but 5TB for 10€/month is still worth it.
So if you're looking for a good hoster and you don't need tremendous amounts of traffic, go for TransIP, they're great. Also, consider running some Tor relays too, you may get a cool T-shirt ;)