I like both the AW Ultra and my Garmins 🤷🏻♂️ What I miss, is ALL my data from Garmin to sync to Apple Health. If that was possible, I would use my Ultra during the day and my Garmin when running.
Here in the northern part, I wear my Garmin on my jacket and use a HRM belt to track my puls. The ultra is not easy to use with gloves 🤷🏻♂️
Have a look at the following apps: RunGap and HealthFit for syncing your data from GC to Apple Health.
For training metrics and workout planning, the free website
Intervals.icu is significantly better than Garmin Connect and syncs to and from a number of other health platforms (including GC). It's got an easy workout builder and planner and will match up planned and executed workouts. It will pull in all Apple wellness data including sleep, HRV, RHR, weight, body fat %, calories consumed (via myfitnesspal) etc, etc.
You can log illness, injury, and pretty much anything else you can think of (such as working days etc - see screenshot). It auto calculates training load and zones. My main training method is usually polarised - eg lots of Zone 2 with short Zone 5+. You can create seasons for easy comparison against past performance and you also get information showing where you sit against others in you age range (and you can compare against other demographics).
I can build workouts to save in my workout library and export them directly into Zwift for completion on my Wahoo Kickr Bike.
When looking at an activity, you can add any graph you can think of and compare any metrics. It can auto detect intervals or you can manually add them yourself. It'll auto detect FTP and pull all best power readings and all timings such as 5s, 1min, 20min etc.
You even have the ability to share your data with coaches and they can directly add workouts to your calendar and monitor your compliance and performance.
The point is, there's better platforms than Garmin Connect that are device agnostic.