I have always had good luck with Lowrance/Eagle. Had several units. I bought a Bottomline 320 almost a year ago and put it on the bow (trolling motor). Never liked the unit. Worked okay, but prefer Low/Eagle much better. The 320 pixels just doesn't look as smooth and detailed as the comparable other units.
The bottomline is in the garage, been replaced with an Eagle.
Might just be me.
Dayton