VA Smalltalk debugging for GBS (GemBuilder for Smalltalk)

I am looking for information on what debuggers people use in VA Smalltalk and why they use the ones they do. This information will help me plan how GBS (GemBuilder for Smalltalk, supporting a GemStone database from VA) will need to change.

If I understand correctly, there are three debuggers one might use:
- the basic, original IBM Smalltalk debugger named DbgDebugger
- Server Smalltalk debugger (SstDebugger?)
- Instantiations' debugger (StsDebugger)

I believe that everyone would prefer the StsDebugger over the DbgDebugger. I don't know how the SstDebugger fits in anyone's work, and whether anyone using Server Smalltalk would even use a GemStone database at all.

Thank you for your feedback.
Richard