Happy to report that since Wiim reverted me back to the old firmware, the Ultra has been stable on all inputs that I've tried, other then a drop when I first tried PHONO. But after that no issues on that input or Line In. Plus, Chromecast has been 100%. So right now things are great. I have no doubt that Wiim will work out the latest firmware issues and I'll certainly be ready to try when they do.
But first I'll wait to hear what other's experiences are