Which Xbee Shield Is Better?

which one is better or which one would you guys recommended?

1: http://www.nkcelectronics.com/freeduino-arduino-xbee-shield-v20-k20.html

2: http://www.nkcelectronics.com/freeduino-arduino-xbee-shield-v20-k21.html

Does it really matter?

This product is out of production. Please, order the new XBee shield version 3 kit