I have a 2012 retina MBP 2.3GHz model 15'' and I use it for general purpose.I've found a 2010 Mac Pro 12-core/2.66GHz,24GB Ram at 2000 euros(here in Greece).Worth it or not over retina MBP ,because it cannot support 4K(without expensive graphics card) has not thunderbolt or USB 3.It is better for me to keep the MacBook and changed in the future or trade it for Mac Pro?