Denon haven't made things easy for themselves with the AH-D5200s. After using them for around four months, I really, really like them, but they're far from perfect. My short review based purely on sound: they're one of my favourite headphones. There's punchy bass, warm, smooth mids and a well-balanced treble response of well-placed peaks for detail. It's a luxury sound for the masses, and I love it.
But with a retail price of $799 (actual prices range from $400 to $700), and a new generation of good quality budget closed back headphones out there, that recommendation comes with a few provisos. One thing's for sure, they're not making my list of the best budget audiophile headphones.
