RE: Handling after going to 'correct' tires
When was the last time you had the wheel alignment (front AND rear) checked
and set to spec?  And how new/good are the shocks?  My personal experience,
based on first my '85 WEsty and now my '90 Westy, is that there are three
elements to the handling that the driver/owner has control over. First
alignment.  If the front end is way out of whack you will really notice it
in the tracking/handling on the highway.  But also first is the tires ( that
you have taken care of).  How can both be first? They go together.  You
can't get proper alignment on the wrong tires and the right tires don't help
that much if the alignment is off.  Anecdote here:  I have the wheel
alignment done by the local VW dealer, maybe the only VW dealer in the
country that still knows what they are doing on Vanagons and even Buses.
The first thing they did when I first took it in for alignment was go out
and check to see what tires I had mounted.  I asked them what would happen
if I didn't have proper tires on and they said they wouldn't align it,
wouldn't take reposibility if I was running the wrong tires.
So my experience has been that the most significant change I've felt has
been tires (major change but including alignment) and then shocks.  Going
from badly worn shock to new shocks was just as noticable as going to the
right tires.