Remember Lenovo build I posted before, well specs similarly to Mac Pro:
Processor : Intel Xeon X5650 Processor (2.66GHz 1333MHz 12MB Turbo SMT) - 95W 2
Operating system : Genuine Windows 7 Professional 64 1
Operating system language: Genuine Windows 7 Professional 64 - English 1
Form factor: Tower 7x9 Mechanical with Intel 5520 Motherboard 1
Memory speed: DDR3 ECC uDIMM PC3-10600 1333MHZ 1
Total memory: 12GB ECC DDR3 PC3-10600 SDRAM (2GBx6 uDIMMS) 1
First Video adapter: NVIDIA Quadro FX 580 32-core (512MB,DVI + DP) 1
Second Video adapter: NVIDIA Quadro FX 580 32-core (512MB,DVI + DP) 1
Audio adapter : Integrated Audio 1
Storage subsystem : SATA Enabled 1
Configuration option : Internal RAID - Configured by Lenovo 1
Primary array configuration: Primary SATA RAID 0 - (4 HDDs required) 1
Primary array hard drives: 1TB SATA 3.5" Hard Drive - 7200 rpm 4
First optical device bay: Lenovo 16x DVD +/- RW Dual Layer 1
Ethernet adapter : Dual Integrated Broadcom Ethernet 10/100/1000 1
Keyboards: Lenovo Preferred Pro USB Full Size Keyboard - US English 1
Country Pack: Line Cord - US - U, F, D, S, T, L, A Models 1
Publication Pack: Language Pack - English 1
Yes, I know Video card is different , but it costs about same
Bottom line: $7,394.00
With exactly same price, the preference at this point would end up with Software/OS preferences....