I bought an A23 a few years ago.
does it plug into your headset - otherwise how could you hear in the cockpit?
Mine came with an "U" adapter. One side of the "U" is a jack for the standard female headphone plug, this is connected to a 1/8th inch four contact male jack that goes into the radio, another wire comes out of this 1/8th in jack and connects to a standard female microphone jack, another wire comes out of this jack and goes into a 1/8 in. female stereo jack for the PTT (sold or built separately).
and, is NAV a good feature to have too or just a nice add on?
Although mine has it, I haven't used it yet, and can't imagine if, or when I would. I opted for the NAV function because, at the time, I could afford it, and could see no reason not to get it. If the difference in price means that you won't be able to get the radio, I think I would probably get the radio without the nav, especially if I was in a critical area like D.C. I would think that a portable GPS would be a better choice.
have you ever really needed yours?
Never needed either the radio or nav function. Like I said, I got it because I could and needed a "toy" fix at the time. I do use it to listen to the ATIS, but as was noted in another post, that could just as easily be done with the aircraft radio.
One other point I feel compelled to mention. My radio only works on 12vdc. I got the one with the rechargable battery pack, and it will only work with a 12vdc power supply. When I bought mine (3?) years ago they didn't even sell a 24vdc->12vdc converter cord. If you want to be able to plug the radio into a 24vdc aircraft power system I had to build a converter. I didn't even consider this fact when I purchased mine, it seemed to me that since the vast majority of aircraft operate on 24vdc, any new, or recent vintage aircraft accessories would be equipped to operate on 24vdc.
This little diatribe wasn't to turn you away from the A23, as at the time I purchased mine, none of the radios had this ability. I have no idea if any of the current crop do. But one of the drawbacks of the rechargable battery packs, that I have heard of, is that they don't hold a charge for extended periods of time. The ability to plug the radio into the aircraft, thus allowing it to be at max charge when the aircraft power/radio fails would seem to me to be an advantage. Maybe if every pilot considering the purchase of aircraft portable items made these points, and the desirability of such a feature known to the salesmen, the companies would make them to work on both 12vdc and 24vdc power systems.
