Hi Guys,
I work for a University using Drupal 7. Our main site has been migrated to Drupal (hosted internally) but we still have some external sites such as Research sites which are essentially flat html files. Some information for those pages are dynamically created with information from an oracle database. The plan is to eventually migrate everything to Drupal.

We are currently looking at implementing a search engine for the Drupal site and the research sites From what have I read, Solr appears to be the way to go with Drupal, but we also have the option of using the Google Search Appliance as well.

I would like to know what users opinions are of both, particularly in relation to integrating search with Drupal and indexing of content.

Internally some people think Google search appliance is better but from what I have seen of Solr I would be leaning more to using Solr.

Most of these opinions on what to use are subjective though and I am looking for some concrete evidence to say that one search engine is more suitable than the other particularly when using Drupal.

Any opinions greatly appreciated.

Thanks,