I went from Pan F+ to the Efke after hearing so much about it and after working with a few rolls in 120 and 35mm immediately got online and ordered a bunch more Pan F+. I didn't experience the stains you are talking about, but the fragility of the Efke is a pain. And no matter how careful I have been handling the film I still end up with small bits of emulsion missing. I also found that the Efke was not nearly as sharp as the Pan F+, and I was not all that pleased with the tonality. I know other people here have gotten very pleasing results with Efke, and based on that I might experiment with it some more, but for the important shots I'll be sticking with the Ilford - I've used for landscapes in all sorts of light and with studio portraits and have yet to feel let down.
Don't know if this answers your question, but I was just so happy to find a topic that I had some real-world experience with...