I had a 4GB readyboost attached to my system for a month and I didn't notice any difference so I removed it.  If you do a search about ready boost on the web you will find mixed feelings about whether it really helps or not. 

I actually turned readyBoost off as it definetly reported lower numbers in 3dmark06. I know that is a gaming measurement, but additional research via google seems to point to readyBoost actually slowing some systems down (newer HDDs more memory).

 

I do have 3 gb and not 2 gb, so there could indeed be some advantage for you there that I am not seeing ...

I installed the turbo memory module in my 1520 since it was pretty cheap. I really haven't noticed any real difference. Boot up seems improved, but it could be due to my tweaks that I applied. I didn't really try Ready Boost due to the fact that research didn't show any real significant difference with 2 GB or more memory. What you're seeing is probably all you're going to get.

You have 2GB system RAM. ReadyBoost won't provide any benefits!

 

ReadyBoost will provide the best system performance boost if your system RAM is in the 256MB-512MB range

I seemed to get a boost in desktop performance with 2 GB in either machine. However, with 3 and 2GB, ReadyBoost causes mucho disk thrashing after boot-up. Remember, ReadyBoost writes and reads the same info to the flash drive as is in the cache, so there is basically double the background activity. With 3 GB, thrashing is significantly less without ReadyBoost.

 

Without ReadyBoost, when some folders are opened initially, the icons graphics fill slowly. With subsequent opens, the icons are instantly graphic. With ReadyBoost, you need to open and close the folder a number before the icon graphics are stored in cache and you get an instant fill.

 

Overall 3GB gives excellent desktop speed. Even 2GB (without ReadyBoost) is significantly better than XP at 2GB on the same machine. With the low cost of RAM, going to 3 or 4GB is the best option.

 

Dimension 9100, Dual-Boot Win XP / Vista Home Premium, 3.0 GHz P4, 3 GB DDR2 533 MHz RAM, 160 GB SATA II Samsung (XP), 300 GB SATA II Seagate (Vista), 250 GB SimpleTech USB (WD Drive), Nvidia Go 6800 (425/825 MHz - XP, 400/800 MHz - Vista, Vista Driver - 163.75), Dell 1901 UltraSharp FP

Inspiron E1705, Win Vista Premium, T7200 Core 2 Duo (4MB, 2.0 GHz 667MHz), 2 GB DDR2 677 MHz RAM, 120 GB Samsung HD, Nvidia Go 7900 GS - 156.69 Driver, 17” Sharp UltraSharp TrueLife Wide-Screen WUXGA

   I use readyboost in my Inspirion E1705 with 2 gigs of ram when using photoshop, I definitley notice a difference

I just bought the same Sandisk Cruzer in the sales myself - cute and I like the U3 applications! Am running Vista HP with 2 gb RAM on Dimension E521. I do not notice any real difference from ReadyBoost most of the time but have found that if I subject the system to a bit of 'stress' with a lot of multi-tasking, there is a worthwhile improvement. For example, I can use the Vista Speech Recognition to dictate in Word while running AV scans and Outlook  in the background and backing up to Mozy more efficiently than before. Not that I do all that simultaneously too often! So I am just gonna use it selectively.

 

p.s. How good is the Speech Recognition - don't hear much discussion about it but I am very impressed with it....have used various (very expensive) SR programmes over the years but the Vista version has them all beat.