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.
Three-fourths of the Earth's surface is water, and one-fourth is land. It is quite clear that the good Lord intended us to spend triple the amount of time fishing as taking care of the lawn. ~ Chuck Clark