So today I found out that I am eligible for an upgrade to my late 2012 (purchased March 2013) iMac 27" at work (specs in sig). But I also need to make sure that the price doesn't go too high, so I'm trying to weigh the pros and cons. Would most of you rather get by on a 512GB SSD and have the Radeon Pro 580, or go up to the 1TB SSD with the Radeon Pro 575? I currently have a 1TB fusion drive and I'm using about 800GB of 1.1TB. I'm not super happy with the performance of fusion drives vs. the latest SSDs, or even my several year old MBP. Instead of macOS swapping stuff out to a slower 128GB SSD paired to a 1TB spinning drive, I'd rather have all my apps and current projects on the bigger SSD and archive things to an external if I need to. I suppose down the road external SSDs will come down in price and I could just plug it into the Thunderbolt 3 port. From what I understand, the 580 doubles the video RAM and adds another TFLOP or so of performance? Will this give a very noticeable bump in Pro apps that might leverage the GPU? The higher end apps I use are mainly Photoshop, Illustrator, Lightroom and Xcode, and I'll occasionally use Premiere for fairly short videos. I also do a lot of multitasking while testing websites, and sometimes I'll have Windows 7, Windows 8 and Windows 10 loaded up in virtual machines testing those browsers. Sometimes I also have to perform operations on fairly large WordPress databases in MySQLWorkbench. Any reason for me to need a 580? There's a chance I might only get the 512GB and 575, which would suck, but I'm currently leaning towards getting the 1TB SSD with the 575. As for other specs, I was going to order the 4.2GHz i7 and 16GB of RAM and add another 16GB from Crucial or something. Thanks!