I tried one. A 320MAX. I thought it was a great deal. BUT....IT is a piece of crap. I gave it away. I have always used Eagle/Lowrance and tried to save a little money. Wasted. I put it on the trolling motor. It lost bottom, drew random diagonal lines from bottom to top (with out the trolling motor or transom unit turned on) and picked up trolling motor interferance.
If you are on a budget, get the Eagle 320 or 480.
Dayton