Well, I decided to see for myself. Picked up a SanDisk Cruzer Mini and a FujiFilm USB Drive 2.0, both 512MB and a Lexar Jumpdrive Sport 128MB. All were USB2.0 Hi-Speed and were optimized in the driver for speed (versus quick removal). Ran Sandra SiSoft 2004 Flash Benchmark and came up with these results:
Fuji was the fastest with 7602 ops/min
Sandisk was next with 1628 ops/min
Lexar was last with 578 ops/min
The trick is that Fuji handles small files significantly better. At 2MB file, they were all about equal.
The Fuji is the largest of the three, but not big by any means. Also includes Win98 driver, whereas other two require downloading.
At BestBuy, the 512MB units were $149. A noted by Eno, the SanDisk can be had from Buy.Com for only $87, while the Fuji is $193. The Lexar 128MB is only $20 after MIR at Circuit City.