Hi,
I have been lucky to own both.
CL500 and a CL63 (Bi-Turbo).
As these cars are so highly spec'ed anyway, you won't find much difference in internal features etc. However the AMG has the slight edge with the AMG trim, AMG on the Digital dash on start-up (worth it lol) and a few other tell tell signs. (Not withstanding the AMG bodykit).
What was the main difference was performance. The CL is heavy, Mars heavy.
While the CL500 was no slug, the CL63 Bi was a astonishingly quick in a straight line (forget cornering at speed in either by the way). around 4 secs 0-60 for something thats a DFS sofa on crack might sum it up.
The ride was smooth and silky but the power delivery sometimes caught me out on overtaking, and I have had a Blackseries too.
I loved the CL500, but I sold it when a CL63 came up as it does make a difference to me. I did regret selling the CL recently to be honest, but I needed 5 doors and seats and only a E63 AMG S got me away from it, it was that good.
Second only to the CLK Black in my enjoyment so far, the E63 has to grow on me a bit more yet as its much firmer that the CL. Mind you the Blackseries wasn't wearing slippers but I was a bit younger then.
You won't be disappointed in either, but for me a CL63 will always trump the CL500 .. because it is simply an AMG..
Press the go faster pedal..
All
Mighty
God.