I have one, been using it for 2 years, going on the 3rd year. Use mine in the boat and ice. I like the dual beam view the best, even for ice fishing. The unit isn't the best, not the most reliable I have reboot mine sometimes, it just stops responding.
I think it works better on ice when the unit is left over a hole vs moving around in a boat. It tends to freeze up or not register anything when trolling my boat.
I know I catch more fish because of mine for sure. I use to get depth when setting up tipups and bait depths. Sometimes I will see a fish take the shiner and watch the flag pop up as I am setting it up, good stuff.
Bottom line for the price and how it works its a good unit, if you can spend more money get a nicer one.