I'm upgrading from the S7 to the Ultra. There's has been much talk comparing to Garmin devices. I've had many, and currently use and really like the Garmin Epix Gen 2, Titanium/Sapphire.
Each has its strengths, and I intend to use and enjoy both. From the specs, I'd say both have comparable excellent displays, and both have multi-band GPS.
Major points for my use:
Ultra has phone connectivity, while the Epix does not.
Ultra is part of the Apple ecosystem, important to me having iPhones and Macs.
Epix has much better battery life.
Epix will connect to many accessories e.g. chest HR strap (sometimes more accurate), various cycling accessories, etc.
Epix multiple buttons more convenient than fewer multi-function buttons or crown, especially during intense exercises.