Just to be back on topic 
, C7.5 works very well here. I realise, in comparison to many others here, I don’t use large numbers (4-7 Omni, Kontakt, Trilian, Massive etc.) of VSTis but do use a lot of hungry VSTeffects, including 2 or 3 instances of Nebula with rather heavy presets. UAD plugs are a huge help.
I’ve learned to work with my aging machine, and what’s funny, I don’t feel like I’m missing anything 
.
One thing about aging machines (not me!), you get to know them really well, and that makes for a stable system. It’s a shame upgrading seems to become necessary sooner or later.
But…different strokes for different folks,
Mauri.