If you need the USB input, the WiiM Ultra is a must try out. If not, the WiiM Pro may do nicely in any comparison you do.
I’m using the WiiM Pro as both it and the plus allow a 5v external LPS, unlike the Ultra.
Additionally, I’ve added two Cisco Meraki with fiber and transceivers in those boxes leading to the WiiM Pro. It’s quite an outstanding bang for the buck.
(Removed the power supplies inside the Cisco boxes, which is simple.)
Last, the ethernet cable is the most important connection to the streamer input. In my setup, I changed the ethernet cables from the router to the first Cisco Meraki and then from the second to the WiiM Pro using Blue Jean ethernet cables. They do make a difference in the impact in my system: BJC Certified Cat 6 Cable, with Test Report, Assembled in USA
Before you commit to $1,000 - $1,500, you deserve to do a comparison in your system. You may be amazed at the results.