I've got two handhelds. I bought a Vertex Standard (read Yaesu) one a while back that also does the 2M ham band. It works well enough. I never bother with the nav side of the thing because I've always had a Garmin handheld GPS (195) and now have several GPS-enabled phones/tablets that do a better job of nav than the Yaesu ever will. The other is a dumb sportys handheld that I bought used off a boardie here for small $ as it was missing the antenna. I put a junk antenna I had on it (it was a 144/440MHz dual band off Margy's old handy talkie). Sitting in my house about three miles from the control tower at IAD I called clearance delivery and they confirmed it worked just fine. It's actually the one that's sitting on the window sill here in the house when I need to talk to someone in the pattern. I've got a UNIDEN scanner (another $10 Ebay find) that stays stuck on 122.9 and wired into the house audio system.
If you're going to use this for emergencies, what you need is one that takes AA batteries and keep a spare set of alkalines around with it. If you plan to use it regularly, a second rechargeable pack may be handy. If you own the plane you're using it in, you can consider installing an external antenna (or as my radio guy did just put a BNC connector right under the panel for the regular radio that you can unhook and connect to the hand held.
I've never in 20 years of airplane ownership needed to use my handheld in an emergency situation. I did bring it with me to Australia and loaned it to another member of our group whose comm radio in the plane crapped out.
I have had to use the handheld GPS a number of times. Navigation is more important than Communication.
Years ago, I was hanging around the airport and Margy's instructor said he was going up to give someone an IPC. "Come along, you'll learn something," he says. So I'm in the back of this student's Arrow. Of course, Buzz's standard lesson is to fly somewhere for dinner (I swear he only starts looking for students when he's hungry). After dinner, we start doing the instrument work in earnest. We were out shooting the NDB approach into GAI if I recall when the student drops the gear and the panel goes dead. Apparently, the alternator had crumped earlier and neither had noticed it. Now it's 1AM and we can see IAD. Buzz tells the student to call IAD on the handheld and tell them we have the airport in sight and want to land. This guy calls Dulles and they give him a squawk code which he is then trying to dial into the dead transponder. The student's just about shut down at this point and the instructor is flying. He says "Give Ron the radio." I call IAD, except the stupid handheld battery is dying. I can hear Dulles, but they can't hear me. They are trying to relay off passing airliners to me but my transmissions are not getting out. Finally we get a call "We have a primary contact 12 NE of the airport, if that's you, turn 270." I yell the instruction to the instructor and he turns. "Very good, if you would like to come to IAD, fly 230." (This heading takes us to the field.) I yell 230 at the instructor and we head in. We're cleared to land and as we're touching down they say that unless they hear from us they will roll the equipment. I transmitted that we didn't need the equipment. They heard that, but when I told them we were going to Taxi to Hawthorne, the radio was completely dead. We just taxied in. The instructor went to debrief the student. I called the tower on the phone and let them know we were OK and thanked them for their assistance.
Moral: Keep alkaline AA's available for the radio and KNOW WHAT TO DO if you need to use it.
