I’ve not tried a DHX RC4 but I liked my CCDB up to a point. They have a huge range of adjustment but they always feel like a CCDB (I fiddled plenty but generaly came back to nearly the same settings as everything else caused compromises). I loved the feeling of plushness at high speed but it’s low speed and techy riding characteristics lead to pedal strikes; add the general lack of “pop/playfulness” and I looked elsewhere for its replacement rather than trying to get someone to custom tune it.
I’m sure they suit a certain type of rider and conditions but just because they have all the adjustments under the sun doesn’t mean they can be set up to feel like different shocks… and other shocks can feel better.
I’m currently loving its replacement… the often derided Fox DHX Air… tuned by Avalanche Downhill Racing 😉 .