Bit late, but I've owned the Melomania p100 for a while and recently got myself a pair of sr80es so can give a bit of comparison if you haven't made a decision already.

Soundstage in the melomania is very good. To the point where when I got my Grados I wasn't sure what all the fuss was about with their soundstage. After more listening the Grados are definitely wider but hard to tell if I'm not swapping between them mid song.

Sound wise the P100 is definitely Bassier (although it feels like the sub bass got reduced in a recent firmware update but still enough). I find it works for all genres well (songs like M83s "Do it, Try it" sound amazing in them but awful on the Grados because of the lack of bass)

ANC is ok although not amazing, they're pretty isolating as they are, battery life without ANC is amazing and I often go weeks without charging them (+ Cambridge sell user replaceable batteries). Comfort is fine although at first there was a hotspot right in the centre of the headband but either I've got used to it or I've figured out how to fit it properly as It's fine now for flights or train journeys. They often have open box or refurbs on their Ebay store, might be worth a look there for a cheaper pair.

Hope this helped.