Dave,
I think you are ok, because you are using only a few instances and another thing, your computer CPU might be the 4 core one. My understanding with these CPU hungry plugs, that number of cores do matter most, not the Ram. I am greedy and do not use plugins in orthodox way. I like to slap them everywhere I see fit smile

I did not mean to put people on defense, sorry if I did. Izotope makes nice VSTs and price is right. But in my case it, Fabfilter works better for EQ, Comp and reverb.
I picked up Neutron Elements when it was nearly free a few weeks ago. I wonder if it drains CPU same way is advanced. It has couple of nice filters (Exiter and Transient Shaper). Should be a nice option for 1-2 instances.