There are some great options and if a person is willing to take a previous generation of unit, there are real bargains as well. Garmin is trying hard to compete in the sonar market and recently they have some nice units out. From what I've read and pictures I've seen, the Lowrance has, in the past, had the best looking sonar views. The cost for Lowrance is usually a bit more and from what I understand the learning curve is slightly harder than Humminbird. I have never owned a Lowrance unit, but wouldn't hesitate to buy one if money was not an option. Humminbird has made great strides with the Onix and Helix units to get the same quality of sonar viewing as Lowrance.
I personally run Humminbird units and have been extremely satisfied. My first unit was a 718 to which I added a magellan hand held gps to get gps capabilities on the unit. I then added a Humminbird 798 hd si, and shortly after that a 998 hd unit and networked these. This allowed sharing of way points. Recently with the drop in price of the Core humminbird units, I am currently running the 998 at the console and have an 1199 at the bow. It is my preference to run the larger unit at the bow since that is where I spend the most time. I run a SI/DI transducer on the transom and an identical transducer on the trolling motor. Recently I have added 360 imaging with heading sensor gps, which I am still learning. My goal is to take the 798 unit I have as a spare and add it to the bow fishing location to have "his and hers" units up front. It will be mainly used for mapping, but will also be able to access all the sonar sources, transom, trolling motor, and 360, just like the 998 and 1199. I do not have the ipilot link, but this is another available feature that uses the humminbird units to interface with the terrova trollling motor by networking.
Ultimately, I love to fish rather than operate boat "appliances". Both Lowrance and Humminbird would work for this, but ultimately, due to the ease of operation and costs, Humminbird won out for me. Features of the Humminbird have not only allowed me to find fish today, but because of my configuration, have allowed me, while fishing today, to find fish in the future. With limited time to be on the water due to work situation, this maximizes the use of my available fishing time, which is definitely a big plus.
As you well know, fishing very shallow water, any sonar unit will be somewhat limited in its capability, but even in shallow water, seeing a slight depth change can be beneficial. The Humminbird units that I run are not the top of the humminbird line, but they do the job for me. I would definitely love to have a complete Onix setup. Maybe this will happen when they become "obsolete". Here are some screen shots from the past and you can see some of the views I use. One of my favorite pictures is the 2d. Never underestimate this feature when fishing. If you have any questions about these units/pictures, I would be glad to share what I know, but up in the electronics forum, there are some real experts that are very much more knowledgeable than I about sonar.
Here is the 360 imaging from last week, with crappie. Sensitivity could be adjusted to show the fish out of the water column better, but I was limited in my adjusting time, due to the poles being bent in a horseshoe.