In a similar vein, I've noted the prices of the discontinued FB-2 climb rapidly and it so happens there's one locally at a more realistic price so I gave it a whirl. Very surprised to find it to be so different from the DF. The FB is exactly as it states, very natural feedback and a useful sculptable focused boost. A very practical "tool" for two specific functions. You can't, however, change the frequency of the feedback (I don't think).
On the whole, the DF-2 is more a creative spark for me songwriting wise and the FB-2 a pedalboard tool if one needs. I didn't pick up the latter but might in the future.
Does anyone have any thoughts on the pair?
(Incidentally, there's a very nice video of Boz Boorer (Morrissey's guitarist) demonstrating the quirkier aspects of the DF-2, that inspired me to keep my eyes open for one)
Here’s mine with some fellow classics for a first test