My 20CL's sounds better than the 20EN's on pristine records, you may have a dud. Both are similar suspension wise and under the eye glass. I use the 20EN's on more worn recordings.
The 4000 and 6000 cartridges I have heard do not have the dynamic seperation of the 20 series. I have thrown out a 4000. I have a new 4000 which I will sell and a worn 6000. Condition on these is hard to assess nowday's.
I bought a 20CL from a person who let me audition it on a 4002. It sounded the same on his system as the 20EN. On mine it was clearly better. I put that down to effort I used to restore the turntable (cap kit, setup and system)
Order - 20CL, 20EN, 6000, 4000. The 6000 was a pretty good cartridge but they are rare to find nowdays.
Hope that helps, Beoaus.