I upgraded to spot lock first.. Changed my life, and since you already have spot lock you just need to chew it over. Electronics are really helpful, but I had to really do some research before I could pull the trigger. Other hobbies paid for my electronics, so I didn't have to dig into my pockets (I do allot of metal detecting )
Only thing I would say is since you already have spot lock, I would get whatever you can afford. Just the side imagine on the HB is a game changer in finding things out on the water. But stepping up in tech something like the 360, or Livescope will change your life out on the water. I am not saying you will catch more fish, but I will say that in my experience you will not waste a cast with either. If you like to fish for crappie, or sandbass the livescope is pure poison on them both.. For bass casting and hitting cover on every cast is very helpful. It is allot of money, but I can tell you you will see and learn things about the lake your fishing like never before.
I use the 360 about 40% as much as I use the livescope. But you have to stop and just fish sometimes. Looking at a screen can kill you when your out working a pattern for bass. That is where the 360 shines.. But for crappie, the livescope should be against the law.. I have screenshots of the 360, but I would need to pull them off the HB. If you want to see some screenshots let me know and I will get you some. You have no idea how many fish actually check out your bait, and are curious. But soooooo many will just check it out, and then turn and go back to their little world.
Now with that said.. Livescope isn't for everybody. You really need to tinker with a unit to fine tune and spend some time on the water to get used to it. If you don't like tinkering, the 360 is all I would recommend. If you like tech, and don't mind pushing buttons and adjusting things the livescope is good tool. If you fish a couple times a month, side imaging and standard sonar is prob all you need. You can side image a point and mark a waypoint with your graph and then focus on that area. If you spend allot of time on the water, and you can afford these options it's a no brainer. I have allot of time on both the 360 and livescope and each have pros/cons. If I had to pick one to use so I could put other people on fish consistently, the livescope would be my choice. (reason: I can pick on crappie, sandbass, and other species) and show people/kids what they are catching real time. For half the cost, the 360 will allow you to focus on structure (rocks, ledges, etc) to make every cast count. The 360 can find brush, but it is allot harder to find brush and pinpoint but it can be done.
Here are some clips of the livescope in Perspective mode & forward mode. Perspective mode fishing a boat ramp in the middle of the night. You can see fish on the ramp (bass and gar) Here is a clip of sandbass up on a small ledge. Lazy sandbass fun fishing. I love taking a break from chasing the green fish and picking on the sandbass.Here is a clip of a Giant bass that just wouldn't cooperate. Just hanging out on it's small little piece of wood. I tried everything.