I own both and have over 300 hours of burn in on both of them. Bass is a lot more present with the IE8's (and that's with the lowest knob setting!). Soundstage is much wider with the IE8's and have slightly better treble. The IE7's are more neutral and have more forward sounding mids. Insertion is shallow (ie7), but I manage to get a good seal with both of them using the medium dual flange tips. The IE7's sound sorta like a cross between the IE8's and the SE530's. The IE8's are the most exciting iem's that I have heard and it doesn't need an amp!