Smart pointers instead of GC?

[DythroposTheImposter]

  I'm interested in how the new LuaJIT GC ends up performing. But 
overall I can't say I have much hope for GC right now.

  GC/D = Generally Faster allocation. Has a cost associated with 
every living object.

  C++ = Generally Slower allocation, but while it is alive there 
is no cost.

  So as the heap grows, the GC language falls behind.

  This seems to be the case in every language I've looked at this 
uses a GC.