Here's a good tip that came up at the DAZ Bryce forums: To restart a render at High Priority, first start a new scene and set it to High, then load the file you want to restart . It should now restart at High priority. Works for me on the Mac but I haven't personally tried this on the PC but PC users say it works as well.

Also - the Bryce render estimate in the Normal AA mode does not include the time it tkaes for the AA pass. Since the AA test is pixel based there's no way to estimate that time except by doing the test.

But the Premium modes are pretty acurate after the second pass because they oversample every pixel so there's no AA test.

Hope that made sense!