I have MP6,1 (12core, 2.7GHz, 1TB PCIe SSD, Dual D700s, 64GB RAM) and MP5,1 (12 core, 2.93 GHz, 960 GB PCIe SSD, Sapphire Radeon HD 7950, 64GB RAM) and run Adobe Premiere Pro 2014 on each. Running the same project workload on each MacPro I find the MP5,1 performs smoothly, no hangups, no stuttering and in general allows me to get my work done in a timely manner. However, the same is not true running the same Premiere Pro workload on the MP6,1. Premiere Pro will be slow/sluggish at times, stalls and I have to either force Quit or at times even have to Restart the system to sort things out. When it does run smoothly it's noticeably faster at getting the work done compared to the MP5,1. Both MacPros are running 10.9.3 (latest). I cannot fathom why the new MP6,1 exhibits this behavior and its performance is very disappointing using Adobe's software on it. I suspect Adobe has had more time to iron out the wrinkles on the MP5,1 as it has been around for more years than the MP6,1 which really has only been exposed to the 'field' for just over 6 months. Do others with MP5,1 and MP6,1 also notice this difference when running Adobe Premiere Pro 2014 on both ? Unfortunately, I'm finding I have to use my MP5,1 to reliably get my work done and will with reservation only use the MP6,1 with fingers crossed that it will behave.