The renderer seems to work differently after every revision. My tests on the toys.prj show that v8.5g is a bit brighter than v8.5f, and with v8.5h reflections are handled differently than in v8.5g.
In v8.0j, textures on the wall can be seen, while in v8.5h they are gone.
You might say these are improvements, but they can be frustrating in a production cycle, esp. since the changes are not documented.