Technically I am loosing money as I don't plan on powering down my SP in any foreseeable future.

But like @fbslo said all witness rewards are pretty much public on the Blockchain and @steemchiller created steemworld.org which compiles all that reporting.

I am doing very good witness wise recently. I don't have the really big votes, but many small voters bring me almost into top 30.

Being a witness for the profit is not something I particularly like and I would not suggest it if that is your driving motivator. I am a witness to keep the network that I invest so much time in stable. I would do it without the rewards. I never expected them to happen but people seem to trust my witness capabilities.