Python make systems

What are the benefits and problems with the various Python make-like systems?

note We're using the denotations '(+)' and '(-)' respectively at the beginning of list items to indicate benefits and problems.

So far I'm aware of

• buildit
  • was previously known as pymake
  • (-) seems to be obsolescing: last release was in late 2007
• zc.buildout
  • (+) currently active as of 2010-07-20
  • uses rc-file-like syntax with [sections]
  • (-) python code cannot (?) readily be integrated into config files.
  • seems to place a lot of emphasis on working with .egg files.
• scons
  • (+) currently active as of 2010-07-20
  • configuration files are written in pure Python
  • (+) python code can readily be integrated into config files
  • (-)? use of Python for config files may entail extra verbosity
• waf
  • (+)? Mark says "Benefits as scons but faster"
  • Any downsides? Why are people still using scons?