I think if you provided information about your current system, it would make it easier to provide recommendations.
You have to keep these apart chronologically, mainly because modern ARC sounds very different from it's' older counterparts.
The older ARC was cool, and analytical, and stood very much apart from the juiciness of the CJ line.
Modern ARC is warm without being tube like. It lacks (IMHO) the mid-treble liquidity of the best tube pres.
I haven't heard a modern CJ in like forever, so I have no idea what they sound like today, but Conrad-Johnson, if you are listening, happy to take a loaner for review. :)
My experience with cj and ARC is the cj had a natural warmth and smoothness of texture while still revealing music's subtle details. In a head to head comparison I found the ARC to be cooler with the ever so slight hint of a hifi sound. The fact that I was listening through imperfect electronics was a tad more revealed through the ARC gear.
Elizabeth's comment about the differences between vintage cj and new production is spot on. Anyone who had exposure, for example, to the cj PV5 or 10 will likely remember the "honey-like" sound of those models. I never heard that from any ARC gear vintage or otherwise.