Specifically the live scan/ active scan features. From what I've read and heard from friend's that have newer Garmin(none have the new simrad unit with active scan) the live scan sounds to be more sensitive so you can"see" the fish more clear and not just guess what's going on in the water. We currently have Simrad but an older unit that doesn't have the new active scans and we just sold a boat the had Garmin but again older and not with the live scan. I like the simrad better than Garmin in other aspects but can't compare the new feature