Short question: Should I buy Yokohama Avid TRZs or Yokohama YK520s (or
neither -- something else?)

Background: I want to admit up front that I don't know much about cars
or tires.  However, I do drive one (a car, that is), so I appreciate any
advice.  I drive a 2000 Toyota Solara, tire size P205/60R-16 on
California roads (in other words, this car rarely sees snow).  I drive
somewhat aggressively, although there are many who drive much more so.  
My current tires are Yokohama YK420s.  In spite of their 55,000 mile
warranty, after 40,000 miles the front tires are at 2.5/32" and the rear
are at 3/32".  So, I'm looking for new tires -- ideally, some that will
last a little longer, although of course there are other considerations.  
I have to say I was never all that crazy about my current tires -- they
always felt as though they were "tracking" off in their own direction.  
(But maybe that was my imagination).  Anyway... I read a recent Consumer
Reports article and came up with Yokohama Avid TRZs as a tire that
(according to CR) had "excellent" dry braking, hydroplaning handling,
and ride, and "pretty good" tread life and wet braking.  However, when I
called up my local America's Tire Company (who sold me my last set of
tires), the person on the phone said that they would be a "step down"
from my current tires, and that I would have to work so hard to brake
that I'd end up wearing them out quickly, too.  He recommended the
Yokohama YK520s, which (a little research showed) are made exclusively
by Yokohama for America's Tire Company.  Now, that doesn't mean they are
bad, of course, but I have to wonder if this guy just wanted to sell me
the tires that he had in stock, rather than going through the effort of
ordering me Avid TRZs, which he did not have in stock.

Thoughts?