Thanks all, whatever has changed between 1.6D and 1.6H (dynamic linking?). 
  I'm seeing dramatic speed & usability increases with this 
statically-linked 4.1.0 XFree server (compiled circa July 2001) on this 
Miata 600au.  Mozilla is positively snappy.

The complexity of the source code (for me) has gotten past the point where 
stuff happens kinda "by magic" anymore, it seems.  Maybe I'm just lazy... ;^)

dhop