I have been very, very unhappy with my Yaesu FTA-550.
(1) The battery status indication on the screen is misleading. I checked mine before one flight, it read "half." I figured I was good to go. But then the radio died when I turned it back on and tried to transmit on it an hour later. And this occurred on the only occasion in my flying career when I actually, truly needed a handheld radio.
(2) I tried to remedy this with the Yaesu lithium ion battery pack and charging cradle. But the radio promptly stopped recognizing that battery was installed (refusing to power up), even though the battery was apparently fine per my voltmeter. AND the radio would only power up with the AA pack if I held the power button while inserting that battery pack -- a trick I had to learn from the interwebs, thanks to a guy who had exactly the same problem.
Not a fan of the Yaesu.