Mbpr 15" Late 2013
i7 2.3 ghz
16gb ram
512 ssd
Dual graphics

been using since late 2013, no problem so far.

plan to upgrade to:

iMac 27" 5k 2017
i7 4.2 ghz
8gb ram (plan to self upgrade later to 32gb)
1tb fusion
Radeon Pro 575 with 4GB video memory

will there be significance improvement in terms of performance? i do lots of video rendering, photo retouching, etc. feels like my current mbpr is getting slower and slower by days