I'm pretty sure the addition of mirrors would not affect the performance at all.
Educated opinion right here, folks.
When someone simply says that a suggestion is impossible, it usually means one of four things:
-The person is, as Treynolds described, a chittering bandwagoner who knows nothing of the subject.
-It's not possible for the average user to implement, though Badspot could do it easily.
-It's not possible for the average user to implement, and there's no way in hell Badspot would waste his time with it,
-The thing being suggested is literally impossible. (
http://forum.blockland.us/index.php?topic=87729.msg1598407#msg1598407)