One of the problems associated with the MRC decoders, is there is almost NO documentation on these. In several communications with MRC, they couldn't really tell me anything about the decoder I didn't already know from using DecoderPro on them. Many CV's, even with a booster attached, couldn't be read.
I do alot of decoder installs and of the installs that involve a changing out of decoders, most have been the removal of an MRC sound decoder for almost any other brand of sound decoder.
These were generally because the owner was totally disappointed in either the sound quality, or overall performance and durability of the MRC decoders. Most had problems of no longer working properly, or not working properly. Many would not take any new programming, or would only take part.