Im pretty much 100% casting, and my boat is “hopelessly out of date” (ultrex tm with linked humminbird side imaging at bow and console). I completely re-rigged my 2003 boat in 2015, so 10 years ago my setup was +\- state of the art. Now…its antiquated. I can’t speak to trolling, and I haven’t used the newer Garmin stuff, it literally didn’t exist in current form 10 years ago. But, a couple tidbits not already mentioned that I think apply here.
1) all of the imaging sonars I have used, both Hummingbird and Lowrance, anytime you use one of the imaging views the screen size and resolution makes a massive difference. If you are considering spending to get any imaging sonar, make sure you have AT LEAST a 9” screen, and even that is on the small side. On a smaller screen, the images still look cool, but most freshwater fish sized objects simply don’t show up against the background with that resolution. If 9 to 12 inch screens are not in the budget, I would stay with basic sonar and get a better quality basic sonar—for the imaging views. I’m not 100% clear how this does or doesn’t translate to fwd facing sonar, could be interesting to get some feedback on that.
2) this is an area where the technology changes very very rapidly. If there’s something NEW you want now, you’re going to pay for it. But guys seem to change electronics the way bow hunting guys buy a new bow every year. It’s crazy, literally insane, how much people spend on this. I think there is some sort of tournament fisherman racket where they get a discount, then sell it at a profit a year later to buy the newest, etc. Anyway, some of the big fishing forums you can save a ton of money buying used sonar setups that are just a year or three old.
3) last piece of info I have is that I used to be a big humminbird and Minnkota fan because they had really, really exceptional tech support and warranty service. Over the last five or six years I’ve had a couple issues where I needed help, and things had changed a lot. I got uniformly terrible service over the last few years. I don’t know if this was a Covid hangover thing, or if things have really changed there, but my opinion of their service changed 180°. I might look into this and get some up to date feedback if you start looking at any used stuff or if you intend to keep a setup for a while.