Difference between Type 4, 5 and 6 Naglers?

I read a bit at the TV site...didn't come away with a very solid impression. What's the conventional wisdom in the community on this question?
I'm currently using two long FL telescopes (a C11 and a 7" Meade Mak)...currently. And a nice binoviewer. -Daniel

Well that's a huge subject. Maybe you could narrow it down a bit. Have you read Tom Trusock's articles at the other place (e.g. http://www.cloudynights.com/documents/naglers.pdf http://www.cloudynights.com/item.php?item_id=1723 http://www.cloudynights.com/item.php?item_id=1737 )
Hate to send you over there, but these are pretty good for starters.
--george