Spotchecker,I got my 320 4 or5yrs ago and like it very much. For the price, the unit can do alot. If I remember right,you can for free download a program so you can see what the unit does.If I remember right the 480 is just a little more coin but,you can put a chip,like Lakemaster in it and your all set to go.Back to the 320,I'm very happy with it and would go out on a limb and say it is well worth your time and money.
You'll be happy with it. It's a good unit. I tryed it icefishing once in the flasher mode just for the heck of it,it worked but nothing like my other flashers. good luck