Hi Mike,
It would be an over reaching statement for me to say the CaRX takes care of all of my trace elements but what I will say is that I think it's critical to my no water changes method. I don't think I would have the same results with 2-part. I've been able to run 3 years with two different tanks each and not have issues up to that point.
Beyond that I can't say. I run Triton tests annually to monitor trends but at the end of the day, besides a few known trace elements that are vital, do any of us really know the role of the majority of the trace elements from a coral husbandry perspective? I made it a point to just watch the numbers and not try to dose any that seem ridiculously low just to see if it would affect anything. For instance, my iodine level was not even registering. I still didn't dose for it... Any issues in the tank? Not that I could see.
I made it a point that if I did see issues in the tank at any time that I would do several large scale water changes to hopefully reset the levels of trace elements in the water. I haven't needed to do that yet up to 3 years in both tanks run with this method.
To answer your question, I use TLF Reborn media currently but also used CaribSea media for a number of years as well.