I have. First, there are many versions of Mark's Jose mods out there. To make an honest comparison to a CCV, you will need to find a 100 watt Jose with a dedicated low gain and a dedicated high gain channel with independent EQ (front and back) for both channels, independent masters, and of course, foot switching for the channels. The usual post master controls will be there too for refinement as the clipping selections and a loop. There are only a few of these full on LG/HG Jose's around as Mark didn't make many. Most are shared EQ. These full on Jose mods and the CCV are in the same ball park, but the CCV you will find tighter, a bit more ballsy and usually a little more quiet at higher gain levels. The CCV has about 560 volts B+ as compared to a normal Marshall with around 470V. This makes a hell of a difference in headroom, saturation, tightness, etc.
Steve