I'm writing this review because of the other reviews saying that this drive was too slow. It's not that slow, but it's not as fast as it was advertised (25MB/s read and 18MB/s write).
Here are results from my small experiment:
4GB (2 files) - write around 10MB/s, read around 25MB/s
4GB (12 files) - write around 9.8MB/s, read around 25MB/s
4GB (34668 files) - write around 1.6MB/s, read around 15.3MB/s
If you look at my results, you'll see that the speed depends more on the number of files you have and less on the file size.
For large files, the reading speed is as advertised, 25MB/s, which is great. But writing large files is only around 10MB/s. It's takes around 6 minutes to write 4GB.
Writing a huge number of small files is very slow. Actually, I gave up after 10 minutes of timing and extrapolated the results. In that 10 minutes, I managed to write around 1GB of files on the USB drive. Reading speed is also slower. If you're using it to transfer huge number of files, you might want to zip them up before transferring.
Now to the design of the drive itself. It's huge. The casing is so huge that you might have problems putting a second drive beside this if USB ports are close together. E.g. If you're using it on a Macbook, you'll not able to use this drive with other USB devices because it will block their ports - this is how bad the design is.
The mechanism for retracting the USB stick is cool but unnecessary. You have to slide back and up to get the stick out, and then up and back to get the stick back in. It's not a very good implementation of retractable as compared to the simple Cruzer.
Also , this flash drive comes with the U3 software, which gives you an additional (useless) U3 partition whenever you plug it into a computer. After uninstalling U3, this drive behaves just like any normal drive should behave - hassle-free.
To conclude, the huge case could be the deal breaker for some. The speed is alright, I guess, but I don't have other USB flash drives on hand to compare it with.