The general feeling seems to be that these antennas are "pretty good" for nav, and "pretty poor" for com. The issue is that VOR/ILS uses horizontal polarization, which is fine for an antenna laying in the wing tip. But com uses vertical polarization, not so fine. I have a -10 (larger wingtip than -7 or -9) and have bent the leading edge of the Archer's radiator down (mounted on top of rib) as much as possible, to get as much vertical polarization as possible. I think it's okay as a backup, I'd want (and have) something else on my primary com. But on the ground, the tower is never more than a mile away, so it works just fine. In fact, sometimes better than my vertical but under the fuselage whip, if I happen to be oriented in a way that the whip is blocked by the fuselage.