HD radio is often low bit rate digital so depending on how many channels the station is running it often may perform worse than FM. Good FM with a un corrupted signal (like a live concert feed for example) can sound great, pity there so little of it these days
http://www.engineeringradio.us/blog/2013/11/what-bitrate-is-needed-to-sound-like-analog-fm/
http://www.engineeringradio.us/blog/2013/11/what-bitrate-is-needed-to-sound-like-analog-fm/