I am a proud owner of an ipod 3G (32gb). To add GPS functionality I bought a GPS external device. Now there are 2 apps, doing the same thing: connecting the device to my ipod. Which is better?

BTstack GPS is cheap, this is what I prefer. Are there some disadvantages in comparison to RoqyBT, like Speed Problems or Lower Battery Times?

Can someone tell his experiences?

Thank You,