I just cannot pull the trigger on one or the other. I have the 5F6 into my sparkly Fender 6L6 Class A and have sold off all of my OD and dirt to make room for more amp emulation pedals. I need the logical step past the 5F6. I play classic rock and blues with assorted guitars. Looking for creamy warmth end of the spectrum. From the youtube vids, it seems like the Formula No. 5 is more musical, but the SFT has more headroom. I do record bass, so that seems to tip the scales to the SFT, but that really is not the priority. Any thoughts, opinions and/or wisdom welcomed and appreciated. P.S. If I had room I would probably end up with both, but they both seem to cover similar territory and I only have so much real estate.