New 2015 RiMac:
Display: improved color gamut - not convincing for me, unless you are a professional photographer or video editor
CPU: Skylake : 8-10% improvement in single-threaded and multi-threaded apps
GPU: I'm not convinced, just a rebranded + higher clocked 29x ?
Storage: you get NVMe for SSD and Fusion drives. However, it's ridiculous that Apple sells a cripped Fusion drive with 24 GB SSD as an upgrade. Should have been standard and should have be 128 GB... for that money
No, if you have the 2014 model stick to it.
I'm still going to swap the mouse for the new model. Fed up with lost connection errors due to a flimsy design wrt the battery compartment.