I have had two of these, and one of the subsequent "power series" CSL Stereo Chorus pedals, and they all sounded great, but this one is my favourite. It was made in 1981, but as far as I can tell, there's not too much difference between any of the ones from the original 9 series.
WARNING: The contemporary reissue of this pedal is NOT THE SAME!!!
*Click Here for a comparison of these two pedals*
Recently, I started using a vintage Boss CE-2 pedal for chorus, but eventually switched back to the CS9. The Boss pedal sounded great with a clean sound, but not so great when distortion or overdrive was added to the signal. I tried adding gain before and after the pedal, but the only way I could get it to sound good loud was to turn the amp up. The CS9, on the other hand, sounds great clean and with distortion.
-Warm analog sound
-A little noisy
-True bypass wouldn't be a bad mod, although if you have a few 9-series pedals in your path, the buffers tend to work well together.