It goes pretty dam fast. I have used several Motos in the past and this one sends even on EDGE system really fast. I'm sure data compression plays a big part of it. I really like my ZN5. I passed my rokr over to the wife (she really likes it) for the ZN5. I was kinda worried about it my self but no worries. I don't even see to need to use the WI-Fi to seed stuff over the router. Even browsing the web is fairly fast for non 3G unit.
Indeed T-Mobile EDGE network is pretty damn fast. Probably has some data compression through network which could be true but in my tests T-Mobiles EDGE has surpassed ATT's. I leave my pics on 5MP and I send pic messages in like 10 seconds or less. No problems... Wifi is a plus too dont forget can be used for pics and internet browsing... Phone is the best