I have been using this watch since 11/2015 (swapped to new updated version in 4/2016 as the original one was recalled) and went through couple different Android phones (Nexus 5, Samsung Galaxy Alpha and HTC One M9) and never had any problem with Bluetooth pairing.
And from your posting, you haven't being successful pairing it with your PRIV since you got it last year. The answer seems quite obvious.
Oh I wouldn't be so radical that you change your phone just to suite your AW watch. That's kinda extreme in my opinion. I have a BlackBerry Dtek 60 that's connected to my LG Urbane 2nd edition LTE via Bluetooth. While Bat is right to suggest that you explore the option of using another brand of phone to see if you have a better connection. My experience of switching around phone connections with other phones wasn't any better. Though I'm happy with my overall experience with the watch and phone pairing I don't expect my phone or watch to do tons just the basics. BlackBerry did tweak their Android skin and and more secure authentication systems within the phone but that doesn't mean that Android OS is compromised and won't work. My older Nexus 6p had the same issue when connected to my LG Urbane LTE so I took it to my phone carrier and they verified that the phone wasn't the issue so I was connected with the LG Tech support folks and they recommended that I send in the watch for they think it's a technical fault.