Paul,
Thank you for your feedback.
1. Absent “Try new version” in FF could mean that the app failed to update itself. Please, try clearing FF cache
https://support.mozilla.org/en-US/kb/how-clear-firefox-cache
2. Boat spinning infinitely in GE or loading stuck at 20% in Cesium is the same issue. It has to do with server and not GE/Cesium. We are still to find the cause and fix it.
3. In a sense we’ve switched to Cesium – it is loaded for new users by default.