I'm using custom snap areas in better touch tool Custom Snap Areas · GitBook on my external curved display. It's still in beta I think. Setting the areas up is kind of annoying, since you can't enter fractions of the display like 1/2, 1/3 but once they are set up, they work pretty well.
So I will say, now I am using custom context menu for window zones and I love, love, love it. See screenshots.
I have way more flexibility and create new zones easily. I can create sub-menus to organize.
With drop zones you have to move window all over and if you have a big monitor it can be a pain.
The only thing I miss is keyboard shortcuts to move between zones. But I feel I might be able to script that with BTT. Some how the keyboard shortcut would have to determine where the current window is and then move to another area based on some calculation/formula.