Has anyone used one of these? I'm moving to the northern cape and gprs/edge seems my only option. Now i got a 3g card with the normal antenna that came with it, but would it benefit me to get one of those that i put on my roof and then connect my card to that? (looks almost like TV aerial). has anyone got some facts on this? what would it improve? stabiliity/latency/speed or what? please advise me.