Clarity and transparency starts at the source. Lossless files delivered to a very good dac, is the foundation of a system with a realistic musical presentation. Different headphones and headphone mods can change the "personality" of a system in exciting and fun ways, but can never "correct or repair" damage done to the musical signal upstream. All three components, dac, amp, and cans contribute.
Bone stock 650s sound like a $1500 headphone when properly fed.
Excellent post. Agree with everything you said.