Hi Tinman,
The Research and Analysis Lab is a comprehensive tool for eBay sellers and ecommerce site owners who want to research products to see if they sell well, and compare that with demand. The tool shows you research and demand stats from both eBay and the internet in general. It also contains a ‘What’s Hot and What’s Not’ section, which is great for getting a quick ideas kick-start! The Research and Analysis Labs are great for new sellers deciding what to sell.
The Auction Inspector focuses less on demand and supply and more on finding and analyzing deep product niches. For example, the tool will help you drill down and compare demand for specific models and colors of iPod accessories. Auction Inspector is great for more experienced sellers looking to finely hone their product range and target deep niches.
Hope that helps :)