Seems like the VHF/UHFs get all the fun and GMRS is the last to get picked for the team. We have the short ducky variants, and the long 771 variants. In the 771 realm, we have the namesake Nagoya 771G, and it's clones from Abree and Tidradio, and a similar, but not quite the same, HYS. They range from 2.15-3.5db gain. Hunting for the "best"
antenna for my Tidradio H3s and H8, I have acquired all of them, with varying performance gains over the stock ducky depending on the scenario. My testing isn't SWR based, as that's nearly useless in a handheld, but actual transmit/receive clarity testing on a "local" repeater nearly 35 miles with some small peaks slightly in the way. As a baseline, the ducky can't reach it with either the 5w H3 or the 10w H8.
Now, I have tried the Abree, and it performed OK. Hit the repeater with both radios, but noticeably worse in the H3, some static on the transmit, clear on receive for both, and it degraded to no transmit and sometimes receive indoors (not surprising). Tidradio 771 performed very similar, and either one is a definite improvement over the ducky, if length isn't an issue for you. Next is the HYR, which up to this point was my favorite. 3.5db gain helped just enough to push both radios to clear radio checks and I reliably received indoors, but could still not transmit (also expected). Downside to the HYR is it's a bit thick and heavy, making it especially awkward and tippy on the H3. The Nagoya 771G has similar performance and is marginally lighter and thinner, making it slightly better than the HYR, IMO.
I love my Signal Stick on my HTs for 2m and 70cm, and they are super light and bendy, and don't make the radio top heavy at all. But they are not tuned for GMRS, and the tall one (dual band) isn't any better than the mono as it is enough out of band that there is no db gain out of it. So it performs like a ducky on GMRS, and if you wanted a flexible ducky length antenna, the mono band does work OK. That's how I found the Bandit G. The Bandit G is built like the Signal Stick with that bendy lightweight materiel, but it's both tuned for GMRS, has a bottom loaded coil, and is 2.15 db gain. Despite the db difference between the Nagoya/HYR and the Bandit G, I got similar reports back and reliably hit the repeater with both 10W and 5W of power. Indoors it suffered like the Abree and Tidradio, BUT, the form factor and weight/build makes it very handy, comfortable, and light. Not tippy at all on the H3, despite being long.
Initial thoughts: Is the Bandit G the best? Yes, and no. Depending on use case, the Nagoya and HYR edge it out a bit on raw performance. However, the form factor and design of the Bandit G seems like a worthwhile compromise to place it near the top of my list. I'd place it tied with the Nagoya, choosing the Nagoya for absolute performance and the Bandit G for handiness, followed by the HYR (which does outperform the Bandit, but just), and the Abree/Tidradio clones last. Now if length is an issue, hard to beat the Ducky, but the Bandit G is flexible enough to bend over and tuck in behind the radio if needed.
Left to right: Signal Stick, Tidradio 771, Nagoya, HYR (she thicc), and the Melowave Bandit G