There is many things I can say positive about livescope as well as many things I can say negative. I'll try and keep it at 3 each...but before I list any positive or negatives I want to emphasize its a tool that has a learning curve. Its simply not a plug and play system. IF you want a max clear picture of all the details all the time you need to learn how to use the unit to its full capability.
First positive is it obviously gives you live sonar that show fish in real time. You can see if they are moving around, stationary and also have a good idea of how many are present. Second will be you can tell how they react to a bait. The overwhelming majority of the time they pay no attention but when they do follow or commit to a moving bait you also know it in real time. Third and I almost list it first but it gives a clear picture of structure and cover. The image of structure and cover is far superior when compared to traditional sonar. It is a good tool to scout out the structure and cover in an area.
My first negative would be the cone angle is small. I tell people its more like pointing a rifle than pointing a shotgun. I'm thinking the cone angle is something like 20* wide. If your wanting to watch your bait and you cast just a few feet to the left or right of where the transducer is pointed your not going to see your bait. Second is its something you need to be routinely adjusting to get the best image. You can sit it on auto but your not going to get all the fine details all the time. Water clarity plays a huge factor in when its time to adjust the unit. What works on the main lake in clear water is not going to work in a creek that has colored water. Now let me be clear the unit will work I'm just saying if you want the clearest picture the settings will need to be adjusted. Third is its a power hog. It consumes more amperage than traditional sonar. My first year I had it on my cranking battery and there was a couple times when I thought my motor struggled to crank. This year I bought a 30ah lithium and put it in my rod locker and have nothing but livescope on it thus talking the load off my cranking battery.
The best advice I can give someone is spend time learning the unit. There is some good youtube videos but for every good one I see 10 of people who are simply throwing out hey look at me content and don't really help a new person learn the unit. On youtuube I highly recommend the Garmin webinars for technical advice and The Bass Tank Garmin videos for educating your self on how to fine tune the settings. I would also highly recommend spending two days doing nothing but learning the unit. I would find someone who has a unit and knows how to adjust it and get them to spend time in your boat showing you how to fine tune the unit. Then spend another day alone in the boat with fishing being secondary and learning the unit be the primary focus.
My final thought is don't let my comments about adjusting the unit scare you into thinking you have to be adjusting it every few minutes. I may adjust mine 2-3 times in a 8 hour trip. Even then it only takes me a brief period to get it dialed in. One thing that has saved me a ton of time is having pre-set adjustments saved. I have settings called The Bass Tank, which is their custom setting for a good "starting point". I find they work best for me if you bump the gain down 3-4% from what they recommend. I have another setting called main lake moving bait. This is a setting I saved one day when I had the unit dialed in to see a jerkbait, crankbait, spinnerbait or any moving bait coming through the water. Then I have a shallow water setting saved. I use this setting in shallow or water with a little color. Having the setting saved I simply push a button and the screen instantly goes to the setting I have saved. From there I pretty much only bump up/down the gain a few % pending water clarity.