I've owned both, as well as an SVT-2 Pro. The 400+ and CL are gone, but I kept the 2 Pro--if that tells you anything. 
They were all great heads. I liked the clean tubey tone of the 400+, but it lacked organic character and depth. I liked the warmth and growl of the CL, but it had little versatility and couldn't get very clean. I found that the SVT-2 Pro is the best of both worlds. For my playing styles, I can get both heads' tones out of the 2 Pro.
They were all great heads. I liked the clean tubey tone of the 400+, but it lacked organic character and depth. I liked the warmth and growl of the CL, but it had little versatility and couldn't get very clean. I found that the SVT-2 Pro is the best of both worlds. For my playing styles, I can get both heads' tones out of the 2 Pro.