I think the Deeper works pretty well Ice fishing. It was the Fish Hunter I wasn't as impressed with. But you're right for ice fishing I still think the best bet if you do a lot of ice fishing is to buy a flasher unit like a Marcum, Vexilar or Humminbird for the best results. Better battery life and not dependent on some other device. Also it is exactly real time then.
For open water it is really handy especially fishing the rivers and from shore to analyze the bottom.