I finally braved it and installed all the P5 updaters. I had been running the "out of the box" version for months, and while it was mostly stable, it was somewhat slow after running for about an hour. Well, after the updates, it is ENTIRELY stable (no odd face room or material room issues), and it is sooooooo much faster I can actually work at a good pace. Nice! And I didn't know what I was missing with the atmospheric volume/lighting options. Sha-weeeeet! :)