adder - 12:08 pm on May 1, 2012 (gmt 0)
@Planet, thank you for the input.
The products are essentially the same but the product pages have a different feel on each of the sites... besides in this niche we have hundreds (or maybe thousands) of similar sites competing, selling exactly the same products/services.
About the way I established this was Panda:
I pulled up organic traffic reports from before and after the Panda update, divided the site into clear sections and compared performance for each section to the overall performance.
So, let's assume the dip in overall traffic pre/post-Panda is 20%. All sections that are within this range (+/-10%) I would just ignore. Where the difference is significantly higher, I'd take a closer look.
As far as the reviews section was concerned, it literally stopped receiving any meaningful organic traffic after the update while some better performing sections stayed within the normal range or in some rare cases even improved.