I am just about to buy one of these (G2500 has built in speaker, G2100 plays through car stereo) for hands free speakerphone and GPS functionality. I would like feedback from anyone who has tried either of these:
1. Does the person you are talking to when in handsfree mode here an echo using the supplied external microphone from Seidio?
2. Do GSM users encouter the interference buzz on either model?

Thanks in advance!