I ordered the Audio version which arrived last week and is a perfect, one job done well solution. I guess it comes down to what device you are connecting to. If it is primarily a music related device then the Audio version is fine. If you want to extend into visual and connect via HDMI then the non Audio version is best. At the price it's justifiable to get both and experiment.
The audio on the audio version is extremely good so far, no drop outs, excellent reproduction supporting high resolution audio. For 30 pounds I am very pleased. I see a lot of potential for the little app to evolve too. I'll be adding an audio to each device and doing away with bluetooth totally. Within half an hour I had all the family phones, laptops, tablets etc set up on it easily.
One tip - although lots of apps natively support Chrome cast within their software, any app can be cast foe screen and/or audio from within the little dedicated app. This isn't mentioned in the reviews.