When landing on a station page the audio playing by default is upgraded from 192k mp3 to lossless FLAC.
When your browser (safari!) does not support that you'll get the 256k mp3 stream automatically. You can tell you got the FLAC stream by the instant starting of the stream; Ultra Smooth 5000™
The streams from the Iphone app have been upgraded from 128k aac to 256k mp3. The aac streams from all stations have been deleted.
May it serve you well!