There is no fixed answer to your question, as performance may vary depending on a variety of factors. Despite having the same networks integrated and the same waterfall setup, performance could be different between the mediation platforms. In my experience, what works well for one publisher might not work for another, so using someone else's results as a benchmark could also be challenging and might cause big disappointments.
I would consider:
- what support can I expect from the mediation partner, will they assign you with an account manager with technical support on short notice?
- will the dashboard and built-in reports give me the KPI's and stats that I would need?
- what data on user level/user activity will they provide? You would want to track ecpm, but more importantly ARPDAU (average revenue per daily active user).
- how easy is it to set up and maintain ad placements?
- how is their bidding offering?
Ask the partners you are considering for a product demo, and maybe you will feel more confident in making a decision. And - if you are not seeing the performance you expect, you can always change. PS: you might be offered a signup bonus if committing to stick to the platform for xx amount of time. My advice would be to not take that risk and rather keep the opportunity to move to a new platform.
If you haven't chosen your partner already, best of luck in your hunt for the best mediation partner.