To elaborate on my feelings on their models, as far as I know:
Fireball - Raw as all fucking hell, lots of high mids and thus potential for nasaliness if tweaked wrong (this is just the Engl sound, so just assume it for every one of their models). Check out the tones on the first two Scar Symmetry albums for a good idea of its tone; they're quite different in some ways, but I feel that owes more to different cab/guitar/mic/something choice, as those dry upper mids are still there from the amp. I dunno, I think it's kinda cool.
Powerball - Like the Fireball, just more unpleasantly grainy; more channels/options, but not more tone IMO!
Blackmore - Can't really say, don't have much experience with it (and haven't heard many clips), but I'd say a slightly tamed Savage
Savage 120 - THE definitive Engl amp IMO; listen to Dimmu's In Sorte Diaboli or Ola/Goddamn Guitar's clips; I still lust for a Savage honestly, it's the perfect refinement of that Engl sound IMO!
Invader - Super middy, djent machine - no thanks (maybe it can do more, but I have yet to hear a clip that didn't sound djenty tone-wise, even if the music wasn't!)
SE - Everything and the kitchen sink!