The Beyerdynamic RSX 700s are an extremely good, Award-winning pair of RF headphones. You get a simple, cigarette-holder-sized transmitter that can also double-up as a charger when you attach the headphones using the bundled cable.
The headphones look fairly snazzy and are comfortable to wear, but they feel rather plasticky and the casework echoes when you click the buttons on the cups.
It's also worth pointing out that, like the Sennheiser RS160s, these Beyerdynamics have a range of ‘only' 20m. That's unlikely to matter to many listeners, but bears mention.
Of course, it's the sound that really counts, and its here that the RSX 700s have always impressed. Play The Mother from The Road soundtrack, and they respond with a balanced, detailed and flowing delivery.
All-in-all they're a pleasure to listen to, but they can't quite muster the punch and overall excitement of the Sennheiser RS 180s. That's why they have to go down to four stars.