g1smd - 4:38 pm on Apr 10, 2011 (gmt 0)
With your new scheme think about what is indexed compared to what is really on the page if you add some comments. User will arrive at a page based on what they saw in the SERPs, but that content will no longer be on THAT page.
Think about how, after adding 5 comments, the new page two is a duplicate of the old page one and the new page three is a duplicate of the old page two, and previously that content was originally on page one. See also that there are up to 5 sets of these duplicate pages (because there are 5 comments per page). Extend this over a long period of time to see how much of an indexing mess this creates.