Here are several related threads, that cover the topics in more depth:

http://www.poolforum.com/pf2/showthread.php?332
http://www.poolforum.com/pf2/showthread.php?5115

http://www.poolforum.com/pf2/showthread.php?15920
http://www.poolforum.com/pf2/showthread.php?14621