Interesting thread. Your results look absolutely more than acceptable. The same as mine with this film also souped in HC-110 (1:50).
In the freezer today, found 2 rolls of Efke Ortho25, which I'd completely forgotten about. Will definitely give them a shot, but I don't think it's available any more. The Rollei films are still of the highest quality, it would take quite a lot to convince me otherwise.
In their instance, the saying is true: "You get what you pay for."