Installer 1.1a represents mostly bug fixes for version 1.1.a
It does a lot more sanity checking on your partitions.
The old installer would basically hang your system if you 
did not have a recognizable BSD root partition.
One addition is an experimental progress bar.  Basically,
I got tired of having to guess how far into the install it
had progressed.  The mechanism I used for updating the
bar displays a lot less granularity on smaller archives.
But on the larger archives it gives a pretty fair idea of 
where you are.  All feedback on the installer features,
or lack thereof, can be directed to sbrown@best.com

Steve Brown