If people are concerned about performance on machines that are 10 years
   old, then they should upgrade their hardware, not complain that some
   algorithm implemented makes access to their bubble memory slower.


some people don't have this option.  lots of netbsd people run hardware
that they have acquired through whatever means and do not have the
resources to upgrade their hardware.  the fact that netbsd runs on all
this old hardware is typically held to be a *feature*.

the above opinion isn't really welcome on netbsd lists :-)