I have a UV-5R plus and can say from personal verified experience, the 771 is not as good an antenna for GMRS use as the stock antenna. It’s optimal TX frequencies are outside of GMRS ranges. I can hit repeaters 13 miles away from downtown Columbia, SC with the stock antenna that I can’t hit with the Nagoya 771. The only thing you gain with the Nagoya is reception due to its length, but that length actually hinders performance across the GMRS frequencies. The 771 is a dual-band amateur radio antenna optimized for use on 2m and 70cm. GMRS is outside those frequency ranges. The 701 is probably better than the 771 for GMRS but it will not get you anything more than you get with the stock antenna.