Will ReadyBoost will make a difference with lots of RAM

I do not yet have Vista (my copy should be through the post next Tuesday) but was wondering from any of you out there who do, does ReadyBoost make any difference when you have lots of RAM.

I have 4Gb of RAM but before reading Toms article was thinking of buying a 8Gb Flash card (they are scarily cheap now) to give a little boost to performance.

After reading Toms article I am debating if it will make any difference at all. I would have through it would if only because the ready boost data would be loaded via flash into memory on boot as opposed via HDD on boot.

I reckon there is about 16-20Gb of data that I regurarly access on my PC, if I added a couple of 8Gb Flash drives plus RAM would this mean most read-access would be either flash or RAM or would Toms article suggestion of it making no difference beyond 2Gb be correct.

Is there anyone out there with Vista who can try it out and let me know results?