I believe RP is a geat product - congratulations to the developers - but there is always room for improvements. I'm going to focus on
SEO:
a) URLs
Spider friendly URLs are a step forward but this would be ideal:
reviews/category_name/product_name
b) Headings
For category and product pages:
<H1>Category name</H1> and <H1>Product name</H1>
c) Meta tags
Use product's description and keywords