I think screen size is just as important as the unit brand. I've got the 5 series Humminbirds, and the screens are really too small to see small details. I can see the big stuff just fine, but they fit my budget and do fine for what they are. Garmin is making a big run at being a player. While I've never used Raymarine, I've not been enticed by any of their offerings. When I eventually upgrade to larger screens, Garmin will be on the short list with Humminbird and Lowrance.
This space for rent