Audirvana is quite good....and simple which is worth a lot. There is also an ios app you can use to control Audirvana via a iPad or iPhone.
Regarding servers, the Aurenders are supposed to be great, but in terms of value, although they are optimized for audio, you are essentially buying a computer. You also need another "real" computer to interface with the Aurender and rip your CD's to etc.. Plus you may need a NAS to actually store your music on.
I am using a Mac Mini as a server. It is connected to an external hard drive via firewire. The mini has a solid state drive and is optimized for audio, and runs Audirvana. It also has a CD drive so you can directly rip your cd's to a digital library (the Aurender products don't.) A monitor is needed for initial setup, but after that you can run the mini and Audirvana headless via an iPad on your wifi network. Super convenient, and you can put together a nice server for about $1200. From the server you would use USB into your dac just like you are doing from your laptop.
As with everything audio, I'm sure there is some sonic benefit from using a dedicated product like Aurender, but the sound coming from an optimized mac mini is great.....plus, it is something you can work on and modify yourself.
