Look at how big shopping sites handle this, in particular ebay since they've gained 20% in traffic this year after recent concentrated SEO efforts.
Nothing is noindex - but the best pages are brought front and center including a category page for every TYPE of item. Gone are all of the fluff pages including forums and even review pages, ANYTHING that might compete with actual category/item pages is gone. Number of fluff links at the bottom of the page are also reduced and condensed.
Yet search for an exact user generated item title and they dominate anyway, even if the page is 50 clicks into a 20,000 results category. The key is getting rid of any fluff and redundant pages, imo.
When ebay has 20 of the same items for sale, with same wording, they now show one item with links to the other 20 from that item page, not from the category page. They've condensed pages but not noindex'd them, it's working.