In a prior post, I expressed some reservations on the new version of the Firestorm Viewer.
I can now report that after six weeks of usage the new viewer is stable. You can install it without recommendations.
Benja and I both thought that the new viewer was somewhat slow when rendering complex landscapes compared with prior versions, but has some advanced features you can read about over at Inara Pey's Blog. We use very different graphic settings on Intel devices, AMD and Apple users may have different experiences.
Benja and I both do clean installs -- something mandatory whenever upgrading viewers due to increasing application complexity.
You can download the new Firestorm viewer, version 220.127.116.11786 at the Firestorm download page: