Lake Superior around Duluth/Superior has very very little structure so the 3 biggest things that I find influenece where Im going to fish are wind, water temps and bait fish.
So having a tool that will give you a better reading of temps at different depths can often be a game changer. I dont know how many times I have been fishing 20′ to high or low and find out later from friends with a temp probe that I should have ben fishing a different depth because od a temp break. To each his own but I believe in having as much and the best equipment you can afford to use.