I am facing the same dilemma but for a different reason. I use bhbr 17 full bed in my Yonex rdis 200 lite and I am starting to have wrist and elbow pain. Also I practiced serves for an hour Sunday and my shoulder has been really sore the past couple of days. I know bhbr is on the softer side for a poly but I guess I might need to move to a multi. I was using ogsm 17 prior to this and was getting really annoyed by the trampoline effect and the fact that my strings looked like a plate of noodles after every rally. I switched to bhbr and wow!! It is incredible the pace, depth and spin I get with it.
I got back into tennis this summer after 12 or so years and have recently started playing daily. It could be that my strokes are improved, but I am really bummed that my arm doesnt like bhbr. Maybe I'll need to improve my arm strength and stroke form before using it full time?