So after installing the EAG650Pro:
- The HDD no longer randomly parks when the graphics cards are under load
- I can run both of my graphics cards (GTX 970+GTX 650ti) without any random freezes (everything including the sound for less than a second randomly)
- I have my GTX 970 running at 1372MHz without any problems, previously it had issues with even a 20MHz OC
- The PSU no longer runs warm/hot
- There is far less interference with the front headphone+microphone jacks
So what I can gather is that the Corsair VS650 really has troubles functioning as a 650W PSU, and would probably struggle in a build as a replacement for a 450W PSU. Functional but well and truly deserving of being included in the tier 6 PSU bracket as it was causing havoc with my rig.