Kinda hard to say because when I got my Sundara, I already had the 1990 Pro & Sennheiser HD660s and I preferred those to the Sundara, so I didn't listen to them much, but when I did I really loved the sound. Honestly, I think if you have a pair of Sundara, HD600 Series or 1990 Pro, more expensive headphones offer little value to you. While I like the LCD X more than the Sundara, I would rather have the Sundara and save the money.