Great question Aquilla!
Could you provide a link to one of your posts that perhaps used that approach? That might be useful to illustrate and perhaps serve as a straw man to work from.
This is a tough one to probably generate concensus on, and I don't know if there is a good answer, but I'll add my $.02 for what its worth.
I try and limit my quotes to provide enough of the poster's argument without just requoting the entire segment. Admittedly, that approach has a bit of a slippery slope to it because if you wind up addressing enough posters and enough arguments, you descend into the novel that you were trying to avoid in the first place.
From an argumentation perspective (putting on my academic hat), rebuttal arguments will invariably result in intentionally dismissing or "dropping" certain arguments from your opponent(s). This is simply the nature of the beast when time is a factor, as I'm sure it is for all of us. The challenge in this approach is not dropping an argument that is critical to the debate. Unfortunately, deciding that is more art than science, since what you consider critical may be different from your opponent. Since there is no formal arbiter of the outcomes on

, naturally your opinion matters most

In the case of multiple opponents on an issue, the restatement approach is probably a good start, but you want to make sure that the necessary points are being addressed. If more than one is making the same or similar arguments, or perhaps it might be useful to group either the arguments that are similar or the authors, depending on which is taking place (sometimes both!). Here's an example:
QUOTE
Both Entspeak and ConservPat are arguing that <Position 1>. I'll address both here:
or, and admittedly this is more time consuming, perhaps multiple arguments are made in by multiple people, but they're basically in the same theme, here's an approach:
QUOTE
Basically there are three points being made by several people(certainly viable to list them here) regarding <Position 2>. They are:
<Summary 1>
<Summary 2>
<Summary 3>
This is all supporting <Counter Position 2>. <insert rebuttal of CP2 here>
This at least makes an effort to condense some of the arguments but makes an earnest effort at giving credit while sustaining the arguments that matter to you.
Note that both of these approaches does not make use of the quote feature. In my opinion that's a bit of a judgement call. Sometimes direct quote is effective, but often its a waste of screen space vs. summarizing the position.
Not sure if this helps, but thought I would add some suggestions.
Doc