I was in the same position. I got talked into the lx7 by a couple guys at the show who had tried/owned both.I also liked that for any service i would need on the marcum would be done in Minneapolis.
I question weather the couple guys you talked to at the show have used the New Helix G2 Ice Series that is New this winter, last years Helix was a quite a bit different than this years Helix7 G2 Ice with chirp, this new Helix G2 has a whole new platform just for ice fishing.
This years Helix 7 G2 has Chirp transducer, includes much improved preloaded basemap vs old uni map, has more screen (view) choices more tailored to ice fishing vs having a simple circular flasher view, includes a customizable ice views vs fixed, better IR (due to chirp), better resolution screen, includes offer to download a free chartselect map upon purchase, has autochart live (make your own lake maps)
Last years Helix 7 Ice – no autochart live, no chirp transducer, less screen resolution, only basic views, low/med/high IR (you can tune out some interferences)
I’ve had both the LX7 and now have this years New model Helix 7 G2 Ice Series and will say after playing with it for awhile I think this is gonna be one nice unit, reminds me of the LX7 but with a Gps and now with Lakemaster maping, seems like a pretty sweet unit.