I wasnt talking about the reflector behind you Kundalini, I was talking about the stoffen. But yes, clean white is always better.
I know you know this, but there isn't always a clean white wall at an appropriate distance behind you. It's always nice to have options. While I don't use a modifier on my speedflash 90% of the time, the other 10%, the shot wouldn't have worked without it.
Sometimes, you just gotta go direct flash or even just angle it back a bit, get close to the subject, and let the spread from the diffuser illuminate your subject. There isn't always something to bounce off of, and when there is not, I would rather have a diffuser than not.