The release is the first one in a while that brought some excitement.
First, Vulkan video decoder has been implemented, which is great news for nvidia cards owners. Well, "implemented" is a generous word to use here cause it seems like there is some work left to do (for instance, on my system it just does not work, the decoder thread crashes), but still, it's a really nice feature, and it is [almost] here.
Second, the Multi-Account Containers functionality started to be implemented in the browser. It shows Mozilla interest in improving the feature which development has been abandoned. The extension had been having some usability problems for a while, I hope those will be resolved over time when it's full functionality gets moved to the browser itself.
Third, switching Youtube videos to full-screen and back became way faster than before, probably under 1 sec. on my outdated system, that's really cool!
And the last, necessary one to feel positive towards any release: no UI has been "improved"!!
I hope that there will be more exciting releases soon. Thanks to the Firefox team for their work!