It is a totally different beast! You can not compare them...it's the CLS processor, but the design took over 5 years of research. The new panels are to my ears, much better. But you will find members that prefer the old technology. There are four double bass panels on each CLX. These are connected bi-polar, and the mid and highs panel, is di-polar. Their sensitivity makes us the possibility to use small power amplifiers. You need only 20Watts/channel to make them to sing.
On the CLS, you need at least, 50 to 60 watts/channel on a tube amp to drive them at normal listening level. What is normal? Around 85 dB to 90dB SPL. If you want more level, you need at least 200Watt/channel for the CLSs. Other thing is that these new CLXs are more friendly to drive. The impedance curve is different, making possible to the use of a wide possibilities on power amps.
I am a tube guy. But I have to tell you that I have being playing with a pair of Bel Canto Evo2MKII modified, and I did like them too very much.
About a week or so, I just made the change back to my tube gear, and my ears are telling me that this sound is more for them. Crystal clear voices, right with the size of the instruments, huge wide stage, with tons of dynamics, a truly experience. I am using in triode mode, and the reed at the sax is a wow! Tons of resolution. I do know that my room is small, but everybody that comes here, their first exclamation is: how did you do this?
The quantity of bass energy at your seating position is very important. If you have too much bass energy, you will have the bass player playing next to you on some notes, and not at the stage, where he or she is supposed to be. So critical listening is advice regarding it.
On the other hand, the CLS, when they sing, are one of the most truthful speakers even on these days. I sold mines to a dear friend, and every time that I am at his place, a lot of home sick comes to my mind. I really miss them. But, then I come here, and listen what I have now, and find my feet tapping along the music, I am very happy too. Happy listening!