As per my 4K thread, I'm now over my 27" phobia, and I'm ready to get a 27" to replace my trusty 2007 aluminum 20" iMac ( to something which will last me another 8+ years!) which has been showing it's age for a fair few months, struggling on basic tasks, and a blue vertical line has appearing in the middle of the screen indicating graphics card problems. My partner works for a company that gives discount on the apple store so I've set a max £1600 budget. My usage and considerations: - I'm happy with 8GB RAM in the 27" and will upgrade to 16GB at a later date if needed. - I want as much 'flash' storage as possible, so the acceptance of the 1TB fusion on the refurb option below is because the flash partition is bigger than the new 1TB fusion which therefore forces me to go 2TB. - My 20" machine has a 256GB HDD, and that's pretty much full (give or take a few GB) - I use the machine to store all my iPhone/DSLR shot photos/videos which is the only large media format on it. - It's powered up 24/7 and is used to run my home CCTV system - Internet/Photos/iTunes/Airplay are it's primary tasks when I'm using it, so it's either small task or large file intensive transfers/tasks. Assumption I need clarifying: 1. All the options below can have their RAM upgraded via a slot in the back of the machine? 1. Refurb (late 2014) 27" 5k + 3.5 i5 (Haswell) M290X + 8GB + 1TB Fusion (£1529.00) 2. New 27" 5K + 3.2 i5 (Skylake) M380 + 8GB + 2TB Fusion (£1,587.60) 3. New 27" 5K + 3.2 i5 (Skylake) M390 + 8GB + 2TB Fusion (£1,653.60) Thanks (again) in advance.