Never used one as a ham, but these and the 321 were the standard radio's I used when in the British Army. Of the two, I prefer the 320, it was just as good as the 321, but much more manageable. Only thing I did not like was the very small indicator on the tuning unit. Otherwise it is just about as straight foreward as can be. Make sure you get a few spare batteries if you want to go portable.
The PRC-320 is a fun HF pack set that is perfect for portable, apartments and emergency use. It is a easy to use rig that is quick to setup and get on the air. You will be surprised what you can do with 40 Watts and a 2.5 meter whip while walking. For me it was E51M Cook Islands DXexpedition, 4816.8 mi (7751.9 km). I paid more ( maround 639 GBP ), but I got a refurbished 320 with lots of extra ancillaries.