Dying flash drive?

[EngDrewman]

I have a 2GB Sony Microvault flash drive that I am having issues with. Recently it has been getting progressively slower and slower, and by now in a fast computer with usb 2.0 it works at about the speed of a usb 1.1 flash drive. The drive is about a year and a half old, and was very fast when I first got it.

I have tried:
-defrag
-removing all data and reloading it
-reformat
-scandisk w/ bad sector check (returned no errors)

none of the above seem to accomplish anything...

I know flash memory eventually wears out; is slowing down a symptom that it's about to kick the bucket?

If it is dead, what brands are the fastest (I run portable apps on it)?