I’ve not had the opportunity to use Oracle’s full text search, but I thought I would offer this link for consideration:
Moving from Oracle Text to Solr/Lucene
I did have the opportunity some years ago to utilize SQL Server’s full-text searching ability (this was first available in SQL Server 7 if memory serves). At the time we were using ColdFusion with Verity as our search engine. I did not see a good way to get around the custom field limitations in Verity, so I searched for my criteria using <CFSEARCH>, then used those results to query a SQL Server database (hopefully using the IN clause instead of querying row-by-row, but it was several years ago and I could not say for certain). Things got much better when I switched to SQL Server’s full-text search as I was then able to do the keyword search and retrieve related data all in one query.
Update: The following article might also be interesting:
Text Search, your Database or Solr
One possible issue with Oracle’s full text search is that there is no provision for faceted search. That might, of course, not be an issue if one can integrate regular queries with full-text queries. This was certainly possible with SQL Server, but I don’t know if Oracle offers this capability.