No slowdowns here. I imagine that a lot will depend on installing Poser 11.2 with "Use existing preference files" checked? Otherwise one's render presets and other speed tweaks might be wiped.

As for the very latest 11.2.x making "rendering ... clearly very different now. The progress bar was different and just not rendering the same way." I would have expected an announcement if there had been such a major change. Can you give us a screenshot of what that looks like for you?

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