I now have to print the toner since 6 months and was 1,400 pages. Remaining are still about 50, wherein the toner is not empty yet. That's more than double, as I have achieved with the official HP toners. Thus, I pay per side approx 1 cent and that's really great!
Conclusion: Each provider has probably its own replicas, but the Druckerpatronenexpress I can only recommend the toner. It saves money and gets more out pages. Price / performance is not only great, but just awesome!