Well, very much against my better judgement, I succumbed and bought one this morning.
My excuse, I thought it would help with the HomeKit Bridge beta testing.
Had an initial glitch with set-up as it stalled with a white screen. Googling the issue determined it was because I didn't have the Apple Music App installed on my iPhone . This obviously slipped through Apple's QA Testing or maybe they couldn't imagine anybody not using their magical music app!
Reluctantly, installed Apple Music and then the set-up completed.
Sound quality is reasonable IMHO and it is quite impressive and as previously reported the HomePod can hear you say 'Hey Siri' even when the music is playing loudly - this is better than an Amazon Echo can handle an Alexa request when loud music is playing.
Airfoil streaming (with a music source of my choice rather than Apple's) seems to work well - Currently streaming from Qobuz running on my iMac in 24bit - 192kHz - not sure the mono HomePod speaker justifies the higher quality music, but a useful test all the same.