Hds12 by far easier graph to manipulate. Humminbird is also a winner. But I would get a helix 12 since it's closer to the hds12 in price.
The Lowrance is easier to manipulate if you are familiar with the Lowrance menus. They are a nightmare for those that have no marine electronics experience and the Humminbird is easier to learn from the start.
I do not have experience with anything other than a 1199. But it is hard to adjust settings (sensitivinty, contrast, ect). It's also hard to switch panel selection. Lowrance has the easy buttons. I find this easier. Takes less time. The hummingbirds downfall is not being able to back track. Once it is off the screen, it's gone. Anything from a freeze to current is also lost unlike Lowrance. They are good units tho. Having the advance settings makes things easier for some. Ford Chevy dodge. But the hds12 gen2 is worth the price different. I love the 10s but they are on a downhill trend.