I have two Lowrance Elite 7s on my walleye boat, networked together, with HDI.
They are awesome units, but I fail to see why anyone would want an ice GPS unit, when it'll just be a battery drain.
I use my Elites in soft water season with the HDI to do high speed reckon, and that's where the Elite series stands out. You can run a specific area, then scroll the chart back and record spots on your chart where there are structures or fish. I actually do this often, works really well.
When ice fishing I move A LOT. As in, if I drill 100 holes, it's a slow day. I sit at a hole for fifteen minutes, if nothing happens I move on. I use a pocket GPS to track my movements and document where I hit something. For me, it's quicker than having a flasher/plotter.