Having had both, I ditched the AW and now have fenix 6 sapphire for less money (~$300 new) than used AW 8. The thing is indestructible (practically), battery lasts for weeks, and it has less smart features and more onboard “stuff”, which I like.

Instinct 2 is now $200 at Costco.

I think the watch technology is pretty mature. I feel cutting edge with a 3 year old watch. Sensor maybe not as good as AW but for anything that really matter you would wear a chest strap hrm anyways.