My laptop will take 2 more GB's of ram. But I'm wondering if a little extra headroom will make enough difference for the expense. Any comments regarding the additional 2 GB? I am running 64 bit so I'm thinking perhaps I should, but I've not priced the ram, yet.

Assuming the existing one is 2 GB.. then plus the new 2 GB, you're going to get is 4 GB ?

Maybe it's better to go 2x 4 GB, if/when the price is ok ? At least taking advantage of 64 bit (may access more than 3plus GB).

Depends on what kind of softsynths you use. If you use heavy sound libraries any addition is good.
That 6 Gb you have is in most cases sufficient. If you don't have any performance problems, then maybe you don't need extra RAM.

I've got 6 GB and would be moving to 8 GB. 

I have Omnisphere and Morphestra is coming soon. I use Orchestral Essentials, BFD, other stuff you see below, and lots of effects. I'm sometimes up to 86% ram usage, or more. I could hit the ceiling if I get much more ambitious. So far, its been ok. But I want to have room to grow if needed. Wii 2 GB really make a noticeable difference? I'm thinking it should at least create a margin for some sonic elbow room. I'd like to own and run some choir libraries.