From my limited experience, extra ram does help stability. 

But I only use my laptop (ASUS G73 i7) for initial scene building. Then I transfer the scene to my home built desktop for rendering, especially for animation. 

I'm saving my money to upgrade my desktop, but will probably only be able to afford
enough to cut render times at least in half.....not bad, but would be much happier if I could render in 1/10th the time.

If you can, I recommend getting a desktop for rendering with an 8 core processor,
at least 8gb ram, adequate power supply, and video card that e-on recommends, 
so it can render while you work on your laptop.

Laptops just can't perform as well as desktop PCs (don't know about MACs), especially when using VUE. I don't know if it's the program's code or just how complex the scene code is, but VUE definitely requires more horsepower to run well compared to any other 3D app I use, most of which run smoothly even on my old HP6226 laptop.  

It's worth the time savings.