Looking for music streamer/server...Is a Macbook Pro better than a Sony Hap Z....

I wouldn't go with a Mac or PC either. Computers, with all the capabilities they entail, are prone to a lot of problems from a sound quality perspective. More dedicated pieces on the audio side will sound better and will be easier to use as well. If you're looking for something that includes storage, you can get something like a Bluesound Vault 2. Alternatively, you can also get something like the Auralic Aries Mini and install a SSD in it. To go higher, you can get something like the Melco N1A which is a very high quality audiophile NAS/Streamer. If you have a DAC with USB input, you can stream from the USB of the Melco to the NAS. Any of these choices will be superior to a Mac option. These are just a number of the multitude of excellent options available.

Agree with Everest for the most part. IMHE, storing library on NAS and then connecting to a streamer/network player connected to DAC is the best option. The other self-contained units with internal SSD are next best approach. Cheers,
Spencer 

I recently switched from using my MacBook Pro to an Auralic Aries Mini.  As is I'd say sound quality is about on par, while the user interface (software) if far superior.  I've added an external power supply and the sound quality improves significantly.  No regrets.

Another happy Auralic Aries Mini user coming from a MacBook Air using USB out to MF VLink 192 to Schiit Gungnir.  ALAC files on external hard drive played by BitPerfect.  Haven't upgraded the power supply on the Aries yet.  It did let me get rid of the long USB cable from the MacBook and I don't have to keep the MBA running.  The Lightning DS app on my iPhone is pretty neat.  Most useful that phone has ever been to me.

SQ is at least as good as it was from the MBA when playing the same ALAC files on ext. hard drive (USB out from the Aries Mini into V-Link and then coax into the Gungnir). BUT I also think I might finally be hearing what people have been saying about Tidal streamed from the Aries (1 yr subscription included in the current Mini's US purchase price).  Before the Aries, Tidal HiFi did not sound significantly better to me than Spotify Premium.  Now, it sounds better than it did before....at least I think it does.   

Yes sbank, a NAS and streamer into a DAC as you're suggesting works very well. It can also come down to how technically savvy someone is as well. The problem I have with Macs or PCs is the knowledge and tweaking it takes to sound their best. To get great sound out of a computer, you often need specialized software to shut down system processes and maybe jitter reducers/reclockers to get the best out of the USB signal. Then you're still dealing with a computer in the room, etc. Many other approaches simply sound better without all the tweaking.