I have used gen 3 smartwatch and I have also used gen 5 smartwatch
• G pay doesn't work and gets disappeared after update it only works in 7 countries as of now.
• whenever I recieve a call on watch the voice breaks almost every time. Voice is not clear
• google assistent does not give messages in voice and don't respond to ok google after turning it on in setting.
• os wear play store sucks and thier are very less useful applications. It has very less content
• You can not download any songs but after using play app of google you can listen to limited songs and if you want to download it than pay for premium.