Windows Vista Ready Boost

Hello everyone, i was wondering if any of you have tried and tested the new Vista READY BOOST?
I have tried and tested it myself – one thing i found out after enabling ready boost by using 256MB flash drive is, it uses the flash drive as a cache and stores all frequently accessed files in it. By doing so it releases the system memory from enormous stress thereby improving overall system performance.Another thing i found out is not all flash drive are accepted by ready boost,particularly those that have a mass storage capabilities e.g 1 and 2 gigs.
Please i am not completely sure if my calculations and workings are extremely correct – if you have anything to teach me more on this topic please do i will appreciate.
Thanks