Using Xbee-Arduino instead of TelosB/MicaZ

I have been trying to set up a small Wireless Sensor Network (WSN). I have worked with Arduino UNO before in a small scale, now wondering whether I will be able to use Arduino UNO+XBee for the WSN with limited number of motes or should I go for TelosB/MicaZ. So far I know TelosB or MicaZ are specifically made for WSN but what could be my strong points to stay with XBee-Arduino instead of using these well used motes? Please share your thoughts.