Hey - 'Fraid I can't help on the Yamaha side of things but I do have a DT770, 80 ohm and a DT150 to hand. They're both extremely comfortable and robust cans. The aesthetics speak for themselves - you like the utilitarian vibe, or you don't. Both probably need some decent amping - the 150 especially. Sound wise the 150 presents a very even handed and natural sound - much like listening to a good stereo. The 770 has a big, slightly undefined bass and a typical Beyer treble spike around 10khz. It's U-shaped more than V-shaped though - it's quite a cool, analytical sound. The 150 is a touch warmer and definitely more about the mids. It still has a big bass though, maybe a touch too much, but it's tighter and the whole can sounds cleaner to my ears. If you're coming from other Beyers (880, 990 etc.) or something bright like a K701 you might find the 150 treble a bit lacking. It's all there though, I think. You might have guessed my preference is for the 150. I do like the 770 though! Hope that helps.