Spotted this in Costco yesterday. Seems to be £20 cheaper than Amazon. This is the info from the Amazon website...
There may be some iPod dock units that deliver a bigger sound from an iPod but the Yamaha PDX50 beats them all for quality and convenience. The PDX50 introduces Yamaha's unique Air Wired technology to give instant and lossless signal transmission to the speaker unit which provides a powerful robust sound through two 8cm speakers. Best of all the PDX50 takes convenience to a new level: the speaker unit can be placed anywhere in the room, while the iPod/iPhone can either be carried around plugged into the transmitter or set down in the handy cradle.
Superior Sound Quality
The PDX50 delivers much better sound quality than other wireless systems. This is because unlike systems that use Bluetooth to send compressed data, the PDX50 uses Air Wired technology to send uncompressed data with no loss of quality from the original recording at all
Perfect Sound Syncing with Movies & Games
Both Bluetooth and WiFi systems transmit data with a delay meaning that when you watch movies or play games on your iPod, the sound is not synched to the images. The PDX50 features real-time signal transmission so movies and games look and sound natural which makes using these iPod/iPhone features a pleasure. Sit where you are most comfortable and play or listen as you want too
Simple Convenient Operation
The PDX50 needs no pairing with the base unit (unlike Bluetooth) - simply plug in the transmitter and away you go. In addition, when you you turn the iPod on and off, the speaker unit turns on and off to save power consuption. You can also adjust the volume of the speaker from the iPod volume control - with most other wireless systems you have to adjust the volume on the speaker base unit. Because of all this you can put the speaker unit anywhere - up on a shelf, on a book case or in an out-of-the-way corner. The iPod or iPhone connects to the transmitter which is so compact you can carry it around anywhere. You can also set the transmitter (with the iPod) in the cradle horizontally on your desk or table for watching videos without having to hold the unit. When in the cradle the iPod/iPhone is charged.
Play your Video-Pods or You-Tube Videos directly from the iPhone/iPod and enjoy a synchronus playback from the video- and audio-signal. The acoustic characteristics are the same that are already used in TSX-series. So you can hear the same powerful and dynamic sound.