Our release binaries are production builds which compile out all of the 
following:
  - debug symbols
  - UT_ASSERTs
  - UT_DEBUGMSGs
  - etc. 
There may also be platform-specific optimizations going on as well.  As 
usual, the net effect of all this is to speed up and shrink the size of 
release builds.  
If you'd rather have debugging information, you can always compile the 
sources with ABI_OPT_DEBUG=1 as either a make argument or a command-line 
variable.  See abi/src/config/abi_defs.mk for more details.  
Paul