Yeah, too bad that they didn't come out with a WiiM Pro Studio with balanced Neutrik combo connectors. I bought one Pro Plus as a test and I ended up returning it. I won't be buying another as it just isn't worth the additional cost. If you are going to be putting better DAC in, you should upgrade the signal path to be truly balanced, otherwise is just seems like more decorative icing on the same cake.The pro plus has a little more space around the connector.
Some cables don't fit in the smaller recess in the pro.
I think the pro plus also has a little more space around the rca output terminals.