I am having a hard time finding flash drives that are small file(s) friendly (read fast write/delete).
The brands I have used: Corsair, Super Talent, Lifetime, Edge, PNY. Capacity range: 2GB - 16GB.
Relatively speaking, they all tanked when it came to dealing with small files (4KB and smaller).
Just recently, I spent a couple hours moving ~13K files (most) under 4KB size. Total amount: 5GB.
All my flash drives are really fast when it comes to dealing with big files (over a meg).
As a test I copied 5 files, each 1GB and that process only took a few minutes.