I have been using Ilford MG IV RC Deluxe and do plan a shift to fiber. But, RC Deluxe has a very nice tonal range and I have been very happy with it. And, I tone all my RC prints in selenium 1:10; it does accept a tone that is very perceptable and gives the right print a very nice visual "pop". But I'm sure it will not tone as deeply fiber; however, selenium does, according to Steve Anchel's book "The Variable Contrast Pinting Manual", provide long term archival qualities to an RC print.