I can't speak much for Efke100, but I use Macophot Up100+, which is said to be the same emulsion, or a very similar one.
The film, like efke, is very fragile, even when dry. An old TRL I previously used made small but regular gashes into the emulsion (probably due to old rolers). The pentacon six I now use made caused some scratches in a few rolls, but I think that is mostly due to the extremely dusty enviroment I was in...
I dry my film in stainless steel reels (hair drier & PVC tube set up), and if the film touches the inside of the reel (like that clip thing), it causes holes in the emulsion as well.
Having said that, it is great film. I shot it at e.i. 200, developed in Diafine. Looking back, I should have shot it at 100 or so, since my film is at least a stop underexposed. Some frames require selenium toning, some don't. You can check out the critique gallery to see what the result looks like (very good to my eyes). The tone is simply amazing, and grain is very small on a 9x9" print (6x6cm neg, though). From severely underexposed negs, that is amazing.
The dye on my film is blue. A deep purple on a water rinse, or a cyan color on diafine bath A (no water rinse).
Well, hope this helps you out. Although the film is not perfect, it is very worth the trouble.