Hello, I have the opportunity to purchase a Mac Pro 4.1 with the following specs for $300. 2 x 2.26Ghz Quad Core Xeon CPUs 8GB DDR3 500GB HDD Nvidia GT120 I am purchasing this computer for the sole purpose of using Sketch (UI Software). I have a Mac Pro 1.1 with Yosemite installed but it is quite slow when there are many layers (designs) on the page. I know that I can upgrade the CPUs but it would also be nice to run El Capitan natively. Given that you were in my shoes, would you upgrade the CPUs in the 1.1 or purchase the 4.1 and sell the 1.1? At $300, the 4.1 is a pretty good purchase no? Thanks in advance.