We've had/have several sets of Kumho tires on our family vehicles. My Corolla had the A/S 795s and now has the Solus KR21s. The only complaint I had with either of these two models is if you let them go for more than about 5K miles before rotating them, you'd get a slight shake at highway speeds that felt like one of the tires was out of balance. Otherwise, very nice tires for the price. Quiet, smooth riding, and good all-weather handling. My Daughter's car has the Power Star 758s, but she's only had them for a few months so I don't really know yet how good of a tire they're going to end up being. She did have them for part of the winter and she didn't complain about poor handling in the snow, so they must be okay there.
Overall, I'd say for the money Kumho tires are hard to beat. I'm sure there are better tires out there, but they're gonna cost A LOT more too.