I've seen those and wondered if they were any better than the lower cost options I'm using. I bought a pair of unknown name units that transmit and receive, for somewhere around $50-60, which I imagine would be around 35 GBP. Most of the time they work fine, with a small amount of low level hiss that's really only noticeable between songs. However, once in awhile they get noisy, often exacerbated by when I walk in front of the receiver. I'd be interested in how well the AudioEngine units perform. If they were hiss-free and rock solid, I think I'd spring for the extra cost.
One of my concerns about the AudioEngine units is that the USB connector has zero length to the connecting "cable." So if the position when it's plugged in to power is not good, then you have to use an A/C extension cable for the USB power converter, or maybe a USB extension cable, neither of which seem to be included in the package.
Dayton Audio also has something like that, and it may not be quite as expensive as the AudioEngine. DA has a good reputation overall. Might be worth checking into.