[doveman2]

But overclocking away, speed won't matter much if you use USB 2 memory sticks no, because the rely on almost the same memory technology as sdcard's. Move to a good USB 3 stick (closer to SSD technology) or a harddrive and database operations will be insanely faster, as high or higher than the numbers we see with f2fs.

Are you saying that, as a class, usb3 sticks have faster memory? If not, I don't see how there would be a benefit over USB2, as the pi' USB interface is usb2, so the faster interface would not help.

USB 3.0 sticks have much faster memory and controllers. Even in usb 2.0, they are faster then regular usb 2.0 sticks.
I noticed noticeble speedups in using xbmc using a ext4 formatted 16GB usb 3.0 Sandisk Extreme stick.

It varies quite a lot actually in my experience. I've had USB3 sticks that were no better than USB2 sticks. USB2 HDDs are generally always faster in my experience than even USB3 sticks simply because HDDs have a much higher throughput than the sticks do but of course there could be USB HDDs that are unusually slow.