Digital Outback Photo have published an informative article on what you should look for in a RAW convertor (first published in Shutterbug magazine):

“To no real surprise, not all raw converters deliver the same benefits in the quality of the output and, more importantly, a good raw file workflow. All current raw file formats are proprietary. That is why every manufacturer features its own raw converter, which works only with files from that manufacturer.”

Website: Digital Outback Photo - Raw Image Convertor Essentials (PDF Format)