At the lower frequency used by Nextel, it is easiet to penetrate buildings and reach a bit beyond "line of sight." You you live in an area where yu get a lot of dropped calls or roaming charges, find out if Nextel covers your area. If they do, a Nextel phone is likely to do well in places that the strict Sprint PCS used by Metro PCS and Virgin Mobile (among others) are not able to maintain a clear signal. For business purposes, it is worth getting a second phone like the i850 to make sure you are always in touch.