Well, my HD 800 is more than 10 years old now, sold all my other headphones after I acquired it and never felt the need to purchase anything new ever since.
With that said, it's always best to try one in-person first if you can as only you will know if it sounds right for you.
Agreed, I gave up on headphones and went for speakers for that reason.
FWIW, the HD800(s) are one of the least problematic flagships sonically. You could do far worse.