Advantages: The first tool is good to see how many links a particular domain has and where they are linked from. Yahoo has traditionally always had the best reporting on back links, so we use Yahoo! Site Explorer for this purpose. The second tool is great for finding pages that contain inbound links to your website and that also contain a specific keyword somewhere on the page. Search engines place heavy weights on the number and distribution of anchor text links and co-cited text that point to a web site.
NOTE: Search engines have been known to favor sites with a distribution of anchor text variations versus a site with many links of the same exact anchor text. Having a good spread of related keywords in your inbound links looks more natural and less artificial.
Limitations: Try our back link anchor text analysis tool to see an aggregate list of what anchor text people use to link to your site, this can be a good keyword and competitive research tool.