@sengha How are you using AirPlay now with your Node? If you are streaming from an iPhone or iPad, the Apple Music app will down-sample the stream to a lossy 256kbps. If you are using a MacBook Pro (according to Bluesound) the AM app will stream at 16/44.
The Cambridge unit you mention uses AirPlay2, so you will get the same lossy stream if you are using an iPhone or iPad. So if you stick to Apple Music, you might not see any improvement.
I believe only Eversolo and Fiio have the ability to get the AM app and a lossless stream since they use an Android OS.