I currently own blue and green stripes, both Simul-Class.
(All green stripes are Simul-Class, AFAIK).
I've also owned the non-Simul (60/100) Mark III blue stripe, and the Mark IV.
The green has 10 more watts in the two Class A power tube section.
This, along with the pentode wiring, gives the green a bit more headroom, and consequently a bit more stiffer feel, especially in full Simul-Class clean settings. In this regard, the clean green stripe tone is closer to the Mark IV cleans.
The blue stripe has a more spongy, bouncy feel, due to the triode wiring.
It's more felt than heard, although the blue does seem to have a more relaxed treble response, also due to triode power.
This is with the same tubes and speakers, by the way.
So if you like more "clank" and "twang" and less "squish" and "sing" in your toans, especially in your cleans, go with the green.
If you demand even more headroom and little forgiveness for even your smallest sloppiness, get the 60/100, and may God help you.
Me, I like a pushed clean that gets dirtier the harder I dig in, so I prefer the blue stripe.
It's important to note that these differences are not large.
I doubt I could tell the differences in a blind listening test, but could probably tell if I played through the amps. They feel different more than they sound different.
I have no idea what "more aggressive" means. More gain? More clean headroom? More treble? More mids? Scooped mids? Less/more compressed?