just changed 4pcs. uc6 205/50r16 at 265 each. came from falken 914 (quiet only if road in good condition). in terms of quietness, it is quieter,  quiet even in rough road condition. haven't try high speed yet coz my car suddenly became a ball, bouncing all the way to office today, until i wanna vomit. speed was below 100. half way went into petro station to reduce air pressure to 29 but still bouncing. Does anyone know what happen?

after check, it was my front absorber went bad. Sorry everyone, kinda like hijacked the thread. Will come back and provide more experience on UC6.

suzuki swift 1.4 gl

yes. it was the absorber. after change then back to normal d. sorry, didn't follow up this thread closely.
In terms of the experience with the UC6, i can say it is more quiet than my falken at any road conditions. below 120km/h, grip is very good.
i no longer speed above that speed, so can't comment for higher speed performance.