Put a new Cooper Zeon RS3-S (305/35 R20) on Ruby today.
I've had good luck with Cooper's before, and the Zeons have had very good reviews in motorsports press, so decided to try this over Nitto's & others favored here.
My initial reaction is very favorable, they launch wonderfully, and have way more grip than the stock Kendas. I know that's not a high bar, but with one short speed run of just 25 miles or so, I'm quite pleased. Passing performance from 40-90 mph was excellent, no squealing, no loss if grip, felt very comfortable as I ran Ruby up to speed on our country roads.
Hope to make a highway run Friday (its bucketing down w/ tornado warnings here this afternoon). I'll let you know how the Cooper does in the fast lane later!
Here's a photo to compare old vs new.