Best standalone music server?

Guys, be careful.  Most of the AC access wifi points will add a lot of noise to the signal that you can't get out even by optical isolation that I'm using as does my Ayre QX5 on it's ethernet connection.  There just isn't any way to get around it.  Even on modest systems like the Bluesound is, the interference is there and can be heard.  

There is no doubt that an ethernet connection is best, but personally, I'd stick with wifi over the AC access point set up if you can't get a direct ethernet connection.  

(and yes, I have tried three different AC access systems to try them out and hated them all).  What I have now done is purchased the EROS router mk3 I believe it is, that has two ethernet connections built in.  I use an optical isolation system, but even without it, I didn't get any extra noise (I was running a very long cable from my other router to check this out), but without the isolation the soundstage will always be a bit smaller and the noise floor is higher.

I've also found that using better power cords on the router has made a fair difference.  YMMV.  

I have not had those problems with my setup. But as you stated YMMV and my home wifi network has not dropped out. When I had an analog rig, could never get used to those pops and clicks even with a good vinyl cleaning. With digital, my audio has never been so black silent when there is no signal. I guess when it comes to unwanted noise, we all have to pick our poison.

Just got a Lumin U1 and extremely happy with it.

For years I used a Logitech (Slim Devices) Transporter. Was always pretty happy with that, but it started showing it’s age once Logi abandoned it, and getting things done through the user forums was excruciating.

The U1 to me sounds far better, and seems a far better built device. I guess it should be at around 4x the $.

Far as ripping, use a laptop and EAC with AccurateRip.  I don't want ripping technology anywhere near my playback sound chain.

The owner of Lumin is a HUGE audiophile. Not all companies are owned or run by someone who's into the hobby.  For you money, The Memory Player and it's less expensive server that I posted about above are the top ones, but Aurender and Lumin are outstanding and great values in their price ranges.  glad you like it.