Upgraded from a series 4 (Nov 2018) to Ultra 2 yesterday (Oct 2023) and I’m disappointed. I’ll continue to add on to this list:
- UW2 doesn’t do precision with my airtags
- Doesn’t do any of its core features better (heart rate, ecg, etc)
- Straps cost 2x more but not 2x more comfy / better quality
- Siri (onboard) is still slow AF
45mm straps fit the Ultra. you don’t have to use the more expensive ones. I use a $3 nomad knockoff.