I decided to write up a review before my track event. I now have just over 1,100 miles on these in size 205/45ZR 17 Y88. This review is a comparison between Yokohoma's ES100 and Kumho's Ecsta 712. I have about 115,000 miles of experience with each, or 230,000 miles combined.

The good:

. Extremely quiet
. Very comfortable
. Zero tram-lining, and I mean zero!
. Exceptional wet weather traction - I don't mean deep water. I would say
they're hydroplane resistence is equal to ES100s or Ecsta
712s. However, grip on very wet roads almost defies reason. It took me a
little while to get comfortable pushing these during the wet weather
these past couple of weeks...simply awsome.
. Dry weather braking - much better feel when compared with the two.
Without testing I cannot say if the Michelins stop shorter. They
certainly feel like they stop much shorter.
. Wet weather braking - far superior to the other two, hands down. Lots of
confidence.
. Weight 20lbs - 1 pound less than the Kumhos...cannot remember how
much the Yokos weigh.
. Dry grip is noticably better; another 3-5 miles per hour on a very
consistent and long entrance ramp.

The bad

. Very soft sidewall. This aspect essential cancels out all the above good
for my driving style and needs. At seven tenths these are incredible
tires. Once past his limit, confidence, as well as the urge to hammer
turns, is vastly diminished. These are not very responsive. I read Tire
Rack's test and this was pointed out, but the degree is subjective and
this is a different car. Above seven tenths, these tire cause the
steering to become very vague and imprecise. The Michelins definately
hang on in these circumstances; dry grip is better as I wrote above, but
getting to this point is not rewarding...nor do they build confidence above seven tenths.

Great tire for a grand touring car.

Cost - $144.00 each