Every tire manufacturer makes a wide variety of tires - some that are great for dry traction and cornering, some that are great in the rain, some that last a long time, and some that are less expensive than others. You can't generalize about an entire line based on brand name. It's all a matter of finding a tire that meets your personal priorities.

Kumho offers some great tires for the money. Their track tires (Ecsta V700 and V700 Victoracer) are about as good as anyone's except the considerably more expensive Hoosiers. Their top-of-the-line performance tire, the Ecsta MX, is excellent - maybe not quite as good as the Bridgestone Potenza S-03, but very very close - and is significantly less expensive than the S-03. Their budget performance tire, the Ecsta Supra 712, is a decent, inexpensive tire, although the Yokohama AVS ES100 seems to be better in every way.

You could say the same thing about most manufacturers' lines. For example, the Falken Azenis Sport is a great street tire for dry traction and an excellent choice for those in areas where it doesn't rain much. But some of the other Falken tires are not as good as those of competitors.

If you're looking for the absolute best performance for a car used primarily on the street, cost no object, then I would suggest the Bridgestone S-03 or the Goodyear GS-D3. If you want something slightly less expensive than those, but close in performance, the Kumho MX is an excellent choice. If you are really looking to save money on tires, then the Yokohama ES100 might fit your needs. There are lots of good choices out there, depending on what's most important to you.