^^: i don't agree, surely they don't increase your default speed, but they do influence the speed at which the file is downloaded, the difference becomes obvious with a connection like mine (2mbps broadband)
with DAP, i get average download speeds of 200kbps while downloading windows vista, and when i stick to my normal firefox downloader, the speed is always fluctuating with a rate between 100-170kbps, mostly around 110kbps