It’s hard to write a thoughtful and technical review about such a complex piece of suspension when in the end all I really want to say how sweet, smooth and plush the RC4 is. Plus I don’t fully understand all the mechanical jargon and technology that goes behind making this shock work.
Most recently I’ve been running the DHX 5.0 and then switched over to the RC4 at the begging of this summer and the change was quite dramatic between the two. The first thing I noticed when I upgraded to the RC4 was how much smoother the suspension ran, this was instantly noticed when just compressing the suspension in the parking lot and also on the rough trails as well. I noticed that the shock shaft is a bit thicker on the RC4 vs the DHX 5.0, I assume this has a bit to do with the smoothness of the shock. Another thing I noticed is that this shock just feels a bit more lively, whether it is compressing or rebounding it just feels better.
Another improvement over the DHX 5.0 was the small bump compliance, my bike previously with the DHX suffered a bit from weird behaviour on the smaller/faster hits, this was greatly improved with the RC4.
In terms of adjustability it has all the standard options such as H/L compression, bottom out, rebound and preload.
So without going into the technical aspects this shock greatly improves the ride characteristics in smoothness and overall ride quality over the DHX 5.0 and I would highly recommend this product.