I am a Contabo customer for the last 3 years. I personally have 2 VPSs from them where I host numerous personal projects and a discourse forum and I administer another one, for the company I work at.
As of now we had almost no downtime (for 3 VPS we had 3 scheduled maintenances that required downtime in 3 years) and we never had any unscheduled issues.
Their support is almost instantaneous, although we have only needed it to use it once to ask something.
In general, they offer exactly what they advertise, and the prices are very-very-very good. I would recommend!