Hay, all good . As I have not yet worked in PS on a any computer with more than 512 of VRAM, I simply don't know what I'm missing. It was for this reason I was asking, to make better informed decisions about any further upgrades to a legacy computer, and all the more a lap top.
As a freelance concept illustrator, though no longer working as much on site, time constraints, and even often limited file transfer capabilities limit working and final file size to be trivial in scale and size. There's simply no need for preliminary work to be maximal size or resolution, as it's not for publication or online use. Again, I am coming to realize I am still laboring under now outdated limitations of my previous work mobile necessities. Many associate production illustrators still working in the field, for instance, work simply on stylus tablets now.
As my work location focus is moving away from field work to more studio based work and even finished or otherwise published illustration, it is the simple case that my work and wallet would be better served by better bang for the buck desk top computing unconstrained by size limitations.
I would now, as of this thread, be more inclined to completely upgrade my Mac computing to as current, maximal desk top hardware with capabilities to more likely last the next few years, as opposed to continue unnecessarily making due and upgrading an old limited lap top. I'd likely go now with a (refurbished) 27-inch iMac 3.5GHz quad-core Intel Core i7 (Late 2013) 16GB SDRAM, 1TB or more Fusion HD, and NVIDIA GeForce GTX 775M processor with 2GB or even a 780M graphics processor with 4GB of GDDR5 VRAM. Or even a Mac Pro MD770(,1,2) LL/A (late 2012) and upgrade it's still ample expansion.