Getting Ready For Vista – Does ReadyBoost Work?

I’m almost ready for upgrading to Vista.  My new mobo arrives tomorrow and I was just about to buy some flash memory to take advantage of ReadyBoost.  If you haven’t come across Vista ReadyBoost, gHacks explains it best:

ReadyBoost is a new disk caching technique in Windows Vista which uses flash memory from flash devices to boost system performance. Caching system resources for small, random I/Os in flash ram is faster than caching them on one of your hard drives which speeds up certain disk reads by the factor 8-10.

Does anyone have experience of whether or not this works, before I whip out the credit card?  I know what’s probably going to happen, is I’ll spend my cash anyway.