Replacing one tire instead of all 4....

I have Kumho 711s wich arent the greatest, but they arent exctas I dont think, they are all wearing evenly. I've heard great things about the traction on the 712s wich arent that much more expensive. I'm sorry you had a bad experiance with them, but they are cheap tires, they are just the best cheap tires IMO

There are 8 models of ECSTA tires that fit into different categories like competition, max performance, ultra high performance and high performance with models V710, V700, MX, EH11, ASX, SUPRA, 711 and HP4, I have the MX tires and they handle and corner very nicely. I also only have them mounted on the front. Some people tires don't match from front to rear because they have wider rims in the rear with smaller tires mounted on the front. And some use drag radials on the rear. Why would he need to change all 4 tires if 2 tires have good tread left?