Yeah I was pretty slow to get on the cell bandwagon. But now I am just as addicted as everyone else.
I have a Nexus 6P and I really enjoy the camera on it. I am not really a techy person so all I can say is that it works for everything I need- it takes good video and photos. The battery life has been good on it but it has only been a year...so it could start to go.
I never use Siri or Bixby so I can't say too much in the way of their imprisonments.