theblueark, you have to hear the blackstone again i think... it clearly cuts much better than the tubescreamers, which sound kind of.. overly smooth. Lets a/b it next time for a better judgement, since I only had my TS9DX to a/b.
With regards to your comment on the screwdriver, on skreddypedals.com, Marc describes the Screwdriver as being "for everything from thin, twangy treble-boost to midrange grit to thick, fuzzy breakup." And the circuitry is includes a fuzz circuitry. If you were to listen closely, the Screwdriver, while possessing the traits of a distortion unit, has this extra fuzziness.
And besides, fuzz for you is big muff stuff. The Hellbilly was a rangemaster fuzz clone but that wasn't fuzz to you too.