My son got me a Sena 5 series (can't remember exact model) for Father’s Day. Anyway the range is really limited in the Hills and cuts out on the curves as soon as he disappears from sight or if someone gets in between us. We are thinking of trading it back in for a 10 or 20 series. I see the 10 has a 300 meter range and the 20 is 1.2 miles, but will they be better in the Hills on the curves and in traffic? Is the 20 series worth the extra money? It would be nice to talk to several people at once, but how well does it work?