Have had these for about a month now, and still can't figure out what a good seal is, or how to achieve it.
i'm using the stock foamies as none of the silicone sleeves (yes, not a single one) fit properly. Sound is very inconsitent with me, with sometimes there is moderate bass, and sometimes when there is very little low end. I'm a basshead flatout, so i guess i'm not too sure what "too much" or "too little" really is.
But overall sound is very good. I've got maybe 80 hours or so on these, and they are definitely showing improvements in terms of treble control. there is much less sibilance than initial listening periods.