There’s a vid on YT with a sound check of the two. Read the comments there and decide for yourself like I did. My “feeling”’ is that the mimby provides richer, deeper soundstage and a more enjoyable experience, if you have the right ancillaries.
But, the D50s is an exceptional performer in its own way and is the centerpiece of an inexpensive two channel mixed media system. Plug in your tv on toslink as an hdmi center for all your streams via roku, fire stick, game consoles, BDP, etc. Add a CD player on coax and a PC/tablet on usb. And, stream via BT. Just add powered speakers or an amp/speaker combo of choice. At $185! It’s a no brainer if your priorities are budget and convenience.
That said, a mimby, tube integrated amp and the right speakers setup well in the right room with the right media would crush it in musicality terms.
Your milage may vary... Cheers!