If the Ultra was bouncing around, you had it on to loose, easy fix.Not wanting a heavy watch bouncing on your wrist when running does not mean one should get a “kids smartwatch”. I would also like a smaller, lighter and more durable Apple Watch.
I used the Apple Watch Ultra trail running for about a month (borrowed a buddies series 1 ultra), and it bounced around so much that I couldn’t keep a heart rate reading. Had to cinch it down to an uncomfortable point to keep it in place.
Happy with my Garmin 265 now, as well, with actual buttons. I never need or use the touchscreen.
But, you're happy with your garmin, that's all that matters