I upgraded from HD650 and it took me weeks and weeks of reading reviews if i would hear any difference going from HD650. The price of HD700 is pretty high but after seeing Sennheiser claiming these were a major upgrade from the HD650 i went and bought a pair. I am in a different world right now, they are so much better sounding. I am using EqualizerAPO with custom presets from Head-Fi which transforms these sets from very good to simply musical nirvana. I use them heavily for music and games and they are truly astonishing. Huge soundstage, amazing...