One star because there is no zero! A total SCAM. Simply do not deliver even close to the speed they sell you. Average 2% of the 40 M they promise. Frequent interruptions. Horrible customer support. Extremely expensive.
When I was registering they asked for all kinds of guarantees to assure that I would pay. When I asked why so much they said "because you are not German". This company should not be allowed to operate.