>I see no reason why "the processing power necessary to do the garbage increases exponentially by the number of bits involved"

me neither,
>
>Sure, you can address more memory and have more objects allocated at the same time than on a 32 bit system.
>But more address space does not necessarily imply more objects

but there might be a special worst case for primitives needing boxing behavior (C# dev intelligence showing through...) as the pointer is now larger and the couple might overflow an internal bus size (think cache) if that has not been increased as well - which might be one of the production problems Tore hinted at...