I really like the idea of SCons. Writing Python is strictly better than using the CMake language or m4. But, quoting one of my colleges: "SCons spends 5min to figure out nothing needs to be done."
Having used both scons and waf, and also having used make, cmake and cargo, I would take any of the last three over scons or waf in a heartbeat. I think cargo is far and away the nicest to use because there is very little to actually do to build your program. Using waf or scons was always an exercise of 'I added a header file, so now I need to figure out the scons/waf API in order to tell it what to do with it'.
At least autotools and m4 have the excuse of all that historical baggage and very broad portability.