The Beyerdynamic DT 770 PRO are slightly better closed-back critical listening headphones than the Sennheiser HD 598 Cs. Their sound profile is slightly better, but they may sound overly sharp for some people. The Beyerdynamic are very well-built headphones and feel more durable than the Sennheiser. Both headphones are fairly comfortable, but the cups of the Sennheiser are more spacious. The Sennheiser also have an in-line microphone for calls, which can be useful if you want to take calls on the go.