i have a Three phone with UMTS. EDGE, EV-DO and UMTS all run around 200-300kbps usually, so fairly fast. GPRS in comparison is about 20-30kbps if you are lucky.
It is quite nice, however the initial connection can be slow. It does pick up a better signal, but beyond (i think) a 65 kilometer radius from the cell, like every other GSM phone (it's a specification in the GSM technology) the signal just dies - cells measure the distance between you and them (via response time) and once it exceeds a certain limit (around 60-70km as i said) the cell says 'Sorry, you're too far away. Find someone closer.' For dealing with this you are better off with EV-DO - it is CDMA based and therefore has no such distance limit.
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