Exactly Harry each according to his own need, one size rarely fits all in prepping. I use PMR446 on .5 watt power for local comms now, but if TSHTF I can dial the power up to 4 watts, but as my mentor light Speed pointed out I can get better performance and range with better antenna like the 771s just as you also point out. My UV5s are retuned to only use the 8 analogue and 8 digital PMR channels so I cannot accidentally intrude on the licenced hams bands, I used CHIRP to reprogram them.
FYI I'm no technogeek but LS helped me design and build a little Di pole antenna with limbs only 160 mm long if I remember right, its ideal for the 2 m 70cm 446 bands and using it my wife can hear me just under 8 miles away which makes it ideal for my needs and retains my security. I'm going to get a President CB rig when funds allow cos that does 12watt SSB as well as UK FM and US AM 27 meg , all legal and licence free. Be a while before i can afford it though.