Rammus changes ?

After playing the 7.10 Rammus changes I've got to say that the 60% slow at all ranks is pretty harsh. I can see how at earlier levels its necessary because his trading in lane is quite good because the magic damage hits harder (top), and the Q speed increase makes coming in for ganks feel smoother. But at later levels I've been feeling quite gimped. My suggestion is to have the slow get less the more ranks you put into W, and take some power from the R's new slow to compensate?