I used to have EL-8 closed and they were terrible. Worst headphones I've ever heard: tonal balance was completely off. I just got my 1770 today and I'm loving them. I had a brief chance to listen to them and found them extremely impressive for a closed headphone: true tonal balance, excellent soundstage and imaging. They best my favorite NAD HP50 in every way. And the build quality is top notch. The only downside is big clamping force. Cannot comment on leakage yet.