I went down that path myself. My older journey is described in my Utopia, Clear, Elex, and HD 600 back-to-back comparison. In 2021 I added the HD 800 S, and it falls between the Clear and Utopia on technicalities. Its timbre, amp requirements, and overall character are more like the HD 600 than anything else I own.
The way to avoid being unhappy with your setup is to avoid A/B comparisons. Dive into music and forget that other products exist. Ignorance can be bliss and habituation to what you have can be bliss. When I don’t compare to other models the HD 600 is still fine.
Edit: I prefer my HD 600 over the Elex, and indeed sold my Elex. I still love the Clear for its easy-on-the-ears treble and easy-to-drive character. No plans to sell.