I will say, the 771G is a pretty fantastic little antenna... SWR on my meter is 1.01:1 on a GM-30. Compared to the stock rubber ducky, I'm able to clearly pick up a repeater 15mi away with the 771G that I wasn't able to even get to break the squelch with the rubber duck. Simplex distance hasn't increased dramatically, 25%-30% maybe, but between a couple HT's that's still fairly significant.
Not a fan of the hard antenna's, even if they're telescopic. As long as you're transmitting in place (mostly static), it's fine when extended... but, if you're oscar mike, good luck with that 48" antenna wandering around, and staying intact (and collapsed, it doesn't work as well as the Nagoya). I can tell you from experience with similar, albeit different brand antennas, they won't survive in my hiking pack, the slightest pinch and the antenna doesn't want to extend or retract, and while I haven't measured the SWR after it's slightly deformed, I'd venture a bet it changes.
