I owned the non-retina 2012, and for me, the difference is night and day. I uploaded the time machine from my non-retina to my 2017 machine and I must say, performance aside, the 2017 doesn't run hot at all, whereas the 2012 machine is nearly hot to touch. I usually register high fan speeds and CPU temps on my 2012 but on the 2017, its cool as a cucumber, even when running the same tasks. I don't see it as just benchmark scores but how the machine has aged in general and it was time for an upgrade.
That said, I have friends who still own the 2009/2010 MBPs and are perfectly happy with them after maxing out their SSDs and RAM. So its all a matter of whether you feel the need to upgrade.