Headphones

They're certainly good cans, I've seen it said that they were even the best money could buy when they were released in 2003 although in a hobby as subjective as this I find that to be a dubious claim.

It’s really up to you. IMO, aside from the timbre (the most natural I’ve heard in any headphone), I’ve never thought of the HD6XX as an end game headphone.

If I was going to a desert island with only one headphone yeah I would Take those. I believe all great and better headphones are inspired by the hd650. Yes there are better ones technically but these are all uku could ever need also.

They can be if they match your preference. To me, they have a beautiful midrange but aren't fun, so I don't reach for them often. But it's all subjective.

For me the point of this hobby is A/B testing. I personally like the sound of Sennheiser and if I needed to pick just one set it would be one from the 6 series (600,650,660). If you just need a good set of headphones it is a good set to stop if you like it. But if you are in it for the sound you will probably be curious to listen to a few other sets also to compare what they sound like (to you). After having compared a bit you could end up to 1-2 pairs and for me for sure HD6xx are fine to end up with.

Depennds on your taste and preferences. You can do better for electronic music, dance, hip-hop etc.

They are hard to beat for vocals and music that is just recordings of instruments played in a space.

Do I think the 6XX’s are endgame ? No. They are very good but not endgame. Paired with a Bottlehead Crack they are definitely much better than out of most other amps I’ve heard and the mids are just awesome. Plug my ZMF Atriums in to the Crack and we are in a totally different experience and yes a better one.