Have to agree with all of this, except the 770s do not actually sound flat once you compare them to studio headphones. They have a swooped sound curve that boosts bass and suppresses mids and highs. Part of this has to do with their closed back design. If you want to hear a more flat sound with all the qualities you mentioned above (minus isolation) check out the DT990s. They are superb for what they cost and they play lower bass and higher treble than the 770s.

A headphone amp really brings out the best in the 770s even in the 80 ohm version. I replaced the pads on mine a couple years back and I'm almost certain they are nearing the 20 years of use mark so their durability is top notch.

I tried to like the AT cans but they sounded bad to me. They seemed mostly focus on looking like dj cans and having exaggerated bass like sony. But a lot of people have been using them for years so they can't be all bad.

The Pioneers are actually all bad. I agree with your assessment of them but it seems there should also be a mention of having either spit on them, thrown them across the room or run over them with a car.