I am using DBX with Delphi 6, and Im happy :)
- With Delphi 2010 Im using the default Firebird driver - only available for Enterprise and Architect editions
- Delphi 2006, 2007 and 2009 I used the CoreLabs / DevArt DBX drivers
- Prior to Delphi 7, I used the default DBX InterBase driver
Now you can also test this free DBX driver which seems very good