I run kumho ecsta ku31's on my 19's for road use. Very impressed for the price but going to swap them out in the New Year for supersports.
At the time I was looking at tyres the ps2's were hard to come by and the m3 guys were talking about the ku31. Good all round tyre with good feedback. For the money I would say they are a decent budget tyre.
They're also wearing very well after being put through there paces on a hot track day and some extremely enthusiastic driving on back roads