That's a bit like comparing apples to oranges really. If I was going with a full screen client I'd have to go with foobar as there are a load of beautiful skins for that.^^^ I'll take LMS with the Material Skin over those for playing local files to the WiiM Mini.
I had thought the mobile version of that skin wouldn't look that good, but I'd say that whilst it's 95% the same as BubbleUPnP there are a few formatting tweaks I prefer - but I suppose some of that is just down to using HTML (and maybe because it only targets a single backend).