Using the RS4 at first was sceptical, as I've previously used ad08r and rs3 which were both great tires too back then. To my surprise, the RS4 has really outperform many others in its class in almost every way possible. Driving on Karak highway at 210+kmh with these gives you confidence and superb steering feedback. Definitely addicted to it and will 💯 buy again

I initially purchased a set of these tires years ago when I just started HPDE. Soon afterwards I decided to try other tires to see how they compared, including the Yokohoma Advan AD08R, Federal RS-RR, Hankook RS3, and Sailun R01.

From experience the Hankook RS4s outperform all of them. Turn in response is very fast, but also very sensitive so it can be slightly difficult for new inexperienced drivers to place the car. Once gotten used to however it becomes very predictable and this no longer becomes and issue. The tires have high lateral grip and the car remains very composed when on the limit, especially during high speed corners. The edge of grip is also quite easy to find and allows you to easily push it without any issues.

Wet grip is surprisingly amazing for an Extreme performance 200TW tire. Dont expect it to grip like PS4s but they exceed the wet grip levels of the other tires in this catagory.

Theres one thing that cannot be argued and its that these tires wear like iron. They are far better than the old Hankook RS3s, which were already great. They havent show any signs of overheating during spirited drives or track driving and grip does not fall off as they wear, so they make for an amazing HPDE/Endurance racing tire where you would be doing several sessions. Reviews by other users support this claim and rave about their wear characteristics.

Unless theres another tire out there that has the same handling characteristics, along with extremely low wear, I will be staying with these tires. This tire dominated the Time Attack event here in NSW Australia, with the majority using them over the Federal RSRR and AD08R. The winner, also using RS4s was only half a second off his best time, which was done on Advan A050 Semislicks (60TW)

1 star because compared to the RS3 they are too narrow for a 9.5" rim. They fit like a 255. I dont have any rim protection now. Waste of money.

I used it on my satria neo cps r3, it was extremely good in the wet and even better in the dry. Gives good feedback on corners, definitely confident on turns. Low treadwear, I didn't get to test them out for more than a year since I sold off the car.

Overall impression
I've used them for 2 autocross/gymkhana sessions and 1 race day. In terms of outright performance, it is up there with the likes of RE71R. It is nearly 40% off the price of RE71R where I live, you can surely guess my future purchase decision.
Dry grip
Like many extreme performance tires, you do need to know an optimal cold pressure and put enough heat into it in order to feel the grip. RS4s are quite resistant to heat, and lateral grip is one of a kind as it does have a thick sidewall. Grip was consistent over two hours of moderately paced race day.
Wet grip
Wet grip is phenomenal and will save you from 100km/h+ to dead stop in a very short distance without locking up the tires. It quickly regains grip from an oversteer in 3rd gear as long as you sensibly modulate throttle. Just make sure you have enough tire pressure as tires will not heat up to an optimal temperature on a cold wet surface.
Wear
What impressed me most was the tire wear as I've done enough donuts during the autocross sections and race day was essentially a 2-hour endurance race. Tires still show over 90% of life left. However, it should be noted that ambient temperature was around 10~20.
Comfort
It will have road noise (like your hub bearing is gone) but it isn't as bad as RS-RR I've briefly used. Moderate to loud music volume will hide them.