I'm quickly approaching retirement, at least retirement from my small business and wanted to get a DAW computer that would work for possibly 5 to 7 years. I prefer working in OSX so that made my choices much more limited.
I tried working with midi/audio over ethernet using Vienna Pro 5 and two Macs but it didn't match my work flow. It works best for users that have set up instrument templates that they regularly access.
The late 2013 Mac Pro is a nice machine but the six-core with the 512 SSD would be the minimum configuration for me. So I was looking at $3900 for the Mac Pro. Then I would need a four bay Thunderbolt enclosure, but probably two of them. So that's another $840. Then I would need a 1TB SSD drive for my samples which would be another $420. I already have plenty of HHD drives. So I was looking at $5250.
That was a lot of money! I started looking around for something a little more affordable and still able to have OSX as my main OS. I ended up buying a ROM flashed 2009 5.1 Mac Pro from a private seller on eBay. It had been upgraded to a 3.46 twelve core with 16GB of ECC memory and a 2GB HHD. Total price with shipping was $2400. Not bad for a Mac that scores over 30,000 on the Geekbench 64-bit multi-core results. This was about twice the 2013 Mac Pro six-core score and close to the 2013 twelve-core score.
I filled the four drive bays with HHD drives and bought a Sonnet PCIe Tempo card and installed a 512 SSD for my boot drive and a 1TB SSD for my samples. This gave me the full 6GB/s connection. I then bought a OWC 5 1/4 optical drive adapter and added a HHD with a 512 SSD for my Windows 7 boot drive via Apple's Bootcamp, piggybacked on top of it. There are two power cords available so one had to be robbed off the optical drive, which can be easily reattached if you need to use the optical drive or just buy a cheap external USB optical drive. This limits the dive to 3GB/s but it's still very fast. You can't boot Windows from a PCIe slot because the Mac thinks it's a external drive.
There is no possibility of Thunderbolt with this Mac Pro but you can add a USB 3.0 PCIe card using one of the two remaining PCIe slots.
So my cost was $3400 for a Mac Pro which is about twice as fast as the six-core 2013 Mac Pro and also is a dual boot OSX/Windows 7 computer. The 2013 Mac Pro can only boot Windows 8.1+ and only on the internal SSD drive so that was a no go for me.
I did also look at Windows DAWs and to get into a dual-core machine you do need Xeons and the price is still up there for a quality build that won't sound like a jet engine.