Hey guys. I am switching from Macbook to iMac and need advice. I design iOS mobile apps. What I use now: 15 inch, rMBP Early 2013, 2.7GHz i7, 16 gigs of RAM, GeForce GT 650M 1Gb, 768 Gb SSD. I work in Adobe Creative Suite apps. What's wrong about it: When files get big (for big apps) Adobe Apps lag. I use scaling to stuff more UI elements into my 15'' retina. Stuff gets small and my head and eyes want to be closer to the screen, so I am constantly crooked and never sit up straight. Hooking up external monitor while doing Skype video call and screensharing slows down the computer drastically (as far as I know because graphics card is an integrated one) What do I want from the upgrade: Bigger screen, bigger UI elements, better posture when I sit. Performance upgrade. To last me two years and stay fast with updated apps. What do I need advice about: 4k or 5k? i5 or i7 (to at least match my current i7) How much GhZ for that processor? SSD vs Fusion (to at least match my current 400 mbps read/write speeds) Apple or 3rd party RAM? Which graphics card? How many GB? Thanks guys.