Ampsettings and the kind of guitar are important with this little green box. Since I have an Orange Rockerverb I don't use it. It makes my amp sound smaller. Other pedals work better with the Orange.
I personally think it has more to do with the amp
Speculation Alert:
Tubescreamers found their place as something that filled out the midrange on amps. IMO some of the most famous cases of tubescreamer use was on American Amps like fenders (SRV) and Boogies (pick your eighties metal band) along with what i call Yankified Marshalls (Stateside Export Marshalls that had 6L6 type valves fitted by the distributers) all of which, to my mind, had a less prominent midrange.
Sometimes i don't get the Keeley/A-man type mods. In the case of the mod+/silver mod they claim to get rid of the unpleasant nasal "midrange hump" that tubescreamers had. Now correct me if i'm wrong, but the whole filling out the midrange thing was the very reason they were used? either as a boost for solo's or to generall cut thru the mix. I think there's a lot to be said for the "less/more drive" mods (which also seem to raise the output, and, depending on the amp, the "tightening up the bottom end mod", because they do result in the TS become a great tight open clear clean boost that adds volume. But it makes the TS not a TS anymore. removing the mid hump takes away what a TS is. Thats why i think the A-man/Keeley "hifi midhump killing" mods are a bit odd. It's like having a slightly more characterful clean boost, but something less than a TS.
Don't get me wrong, the keeley sounds great, and it still has enough midrange to compliment what my amps putting out already, it does add to the low end of my amp too, and the TS9 does sound great doing the glassy gritty thing on a clean channel.
I just think the tubescreamer has been mojoficated beyond all reason these days. Not everyone needs one, if you like it fine, but i know a lot of people who own TS's because "everyone owns a Tubescreamer". Not meaning anyone here btw. I see kids beeline in and out of local music shops with them. especially the 808 RI