From our tests render times were slightly quicker. Although you might have found something weird so it'd be great if you could try rerendering it in OB7 to be sure.
This may be the same problem I had, since OB7 (correct me if I'm wrong) nodes were skipped if you had them on, but in OB8 they are not skipped (partly working nodes, some basic stuff), so if you have any nodes checked or on use, this might be the reason for slower rendering...
Ok rerendered it twice on 0b7 and 0b8 and same results. Seems to slow down on translucent materials in ob8 and I have a few objects with translucent materials. no nodes in my scene, too. I'll do a test render on a different project that doesn't have translucenty materials. I hope its just a glitch because the render time is significant, test renders of 8 min now 12 min and high settingl render of 50min become 70min.
I have rerendered a scene with OB8 and to me it seems to be slower, too, in contrast to OB7. Could it be caused by old OB7 scene settings. There are no nodes or translucent surfaces in the scene.
