They moved my delivery from February to April. Got annoyed with all the wait and decided to change the order from CTO 6c, D500, 512GB to base 6c, D500, 256GB + 3TB Lacie Thunderbolt Drive and receive it same day I've made decision (ordered from local reseller store).
Was worried I'm gonna fill internal SSD fast but now I see I was wrong.
PS, AI, INDD, Aperture, Blender + small apps like coda + games (D3, WoW, SC2, SimCity) + all my recent work + recent photographs took 105GB of internal HDD. Have 145GB left which is more than sufficient amount.
Tested out aperture with library on external drive and internal drive. Found no real difference in speed when working on photos on either drives.
As for overall performance in my work apps it is really great. Retouching 5D3 photos is pretty smooth. (i work with graphics, photography, coding). Blender renders stuff I need pretty fast.
Performance in games, D3 goes on full details always 59 FPS, SC2 got some performance reported issues in latest version but it is ~30 - 60 fps on Extreme details. WoW on High runs ~60 - 160 fps (depends if in overcrowded city or in the field). SimCity smooth and nice on full details. Using 1920x1200 screen and OS X versions of the games.
Only cons. I've found so far is lack of Mic. Had to buy external USB one.
I hope my input is of any use to you