I have been testing out the Sierra Wireless card running on AT&T's Prepaid Pay as you go system by buying the media net feature so far it runs great flawless using wap.cingular apn I also tried using my iPhone data plan sim card which I pay monthly for and it runs even faster got speeds of up to 1.5 + downloaded a 100mb file @ 170-210k using the prepaid sim I download at about 40-80k... what is the difference is it on a different network or something