I've been using Garmin for a long time. They just kept delaying their sidescan and I'm impatient.
I had bad experiences with Humminbird and most likely will not buy another of their products.
Lowrance has always been well regarded so I figured that I would give them a try. Their imaging looked a little better and the 2yr warranty, 5yr support program and $300 rebate made the decision a little easier.