Evaluation of Google Custom Search

http://svensk-medicin.se/ is a Swedish medical search engine based on Google Custom Search. http://web4health.info/en/answers/proj-search-other.htm is a list of search engines, some of them using Google Custom Search, in English. Evaluate either in Swedish or English whether these search engines more often provide good answers to questions in the medical area than:
1. Ordinary Google search.
2. Google search with site: restriction to one or more of the sites included in the custom search.
3. Internal search engine provided by the web sites included in the custom search.

Method: Choose random queries written by actual visitors to medical web sites, I have access to lists of queries to select from. Check the goodness of the search result using the different methods. By goodness can be:

1. Good readable and understandable information on what the query asked for.
2. Not containing spamming or trying to sell something (sidebar ads are OK, provided the main topic is good and the ads are clearly separated from the main content.
3. Medically reliable information, not trying to sell some dubious health cure like penis enlargment pills.

Note: This is not a paid job!