Grimm MU1 vs Antipodes K40

I have the Antipodes K40.  I've never listened to the Grimm.  The Antipodes can be upgraded to the K50 if I wanted to.  Or, I can keep the Antipodes with my Lumin X1, and add a Grimm MU1 to go with my Weiss DAC 502.  Any thoughts from people who've used both servers?  Thanks.

Bill