Used for neuroscience research (OS X), home office (OS X & Windows), and gaming. Installing OS X went smoothly with a couple minor issues. Everything works as expected.
I needed a computer right away so I couldn't wait for amazing component deals but there were some good deals. The prices below are after rebates but before cash back (will take off another $8 or so). I was trying to keep the build close to $750 (no more than $800), including the monitor.
Most components were picked based on TonyMacx86 guides: http://www.tonymacx86.com/building-customac-buyers-guide-december-2014.html
After testing, I can play all my games (modded Skyrim, Tomb Raider, Anno 2070, etc.) at high/ultra quality at 1080p. I'm not looking to overclock, I just wanted something stable that would give me at least a couple years of work and gaming before needing upgrades. I'll probably throw in another SSD at some point as prices come down.
3DMark Skydiver at 15997 and Fire Strike at 5657.
Here's how to get OS X working:
I followed the standard Tonymacx86 guides (http://www.tonymacx86.com/yosemite-desktop-guides/143976-unibeast-install-os-x-yosemite-any-supported-intel-based-pc.html) - the only changes I needed were with the boot switches.
To install OS X via the Unibeast USB I had to use the -x -v -no-zp boot switches. If I didn't, I'd end up with a panic and have to reboot the computer.
After OS X installation but before Multibeast tools were installed I set Mode=1920x1080x32 (and also booted with -x -v -no-zp).
In Multibeast I selected DSDT-Free. The audio codec for this board is ALC892. I also added the recommended 1080p mode and hibernate desktop. I set the computer as an iMac 14,1. I selected SSD Trim Enabler (with 3rd party SATA support checked) and GenerateCPUStates. Apple IGB was selected under network. Also, I made sure USB 3.0 support was selected.
That should be all of the Multibeast options I used.
I had a boot0 error but that was fixed using the instructions in the boot0 Error: The Official Guide post (http://www.tonymacx86.com/general-help/65706-boot0-error-official-guide.html)
Specifically, all I did was the following: dd if=/usr/standalone/i386/boot1h of=/dev/disk0s2
My ethernet isn't working in OS X but I'm never planning on using it since I purchased the excellent TP-Link adapter.
Let me know if you have any questions. The process was quite smooth. I also installed Windows 8.1 on a separate hard drive (installed Windows (disconnect HDD) then OS X but OS X then Windows works well - just rerun Multibeast after installing Windows to make sure you can choose to boot either drive).
Edit 08/06/15: I recently upgraded to Windows 10. I had to disconnect the OS X SSD to get Windows 10 to install but it was otherwise flawless. I've had a couple minor issues with the build - when shutting down from OS X the computer will occasionally turn back on within a few seconds (but it doesn't do this all the time). Weird but not something I've bothered to fix yet. Also, the computer will occasionally turn on at random times (e.g., I'll turn it off overnight and once in a while it will be on in the morning). There's probably a motherboard setting I need to modify to fix that. Again, not really an issue and it only happens on occasion. Other than those minor annoyances, it's been flawless.