In my opinion the Dragon (which I own) is more open and less compressed. There is not a ridiculous amount of gain and I wouldn't describe it as being a tight amp, but with a boost the crunch channel gets VERY thick and retains definition. You can actually get some pretty djenty tones as well with the proper picking technique. The cleans are very chimey and beautiful, best cleans of any high gain amp I've heard.
The solo tone is KILLER and very dynamic when boosted, but you have to be able to play really well to sound good on it-I owned a Madison previously and there is a difference. You have to really dig in with your fast picking runs etc....to me it's worth it for the dynamics. It is a very versatile amp, I play progressive metal, butt-rock, blues and attempt jazz once in a while and it satisfies me.
Never played a Cobra, but from my understanding it is gainier, more compressed, and brutal sounding. I don't think it has the same characteristics with the lead tone. Not as dynamic, probably easier to shred on.
For versatility, relatively organic, thick rhythm tone and singing solo tones (Dream Theater, Lamb of God, Pagan's Mind, Aghora, Porcupine Tree, John Petrucci/Nuno/Guthrie solo tone) the Dragon is PERFECT. Nevermore-styled tones are there but to me it's more smooth sounding.
For total djent and brutal tone as well as a more processed lead tone (Necrophagist etc) I think you'd want the Cobra. Note the Dragon when dialed correctly can do this style of music as well, and the Cobra can be quite versatile.
Honestly, if it says Framus on it it's not going to suck
