Can't say I'm opposed to the, uh, concept of vertical format. I get it, you can only see so much on a phone. Reading the entire page through the simple act of scrolling down is easier then the back and forth of pages. I get that.
The thing I don't care for is the push towards one panel visible at a time. That bugs me because there are so many actions that need multiple panels in context to understand. Fight scenes are obvious but even little things like portraying indecision need implied movement.
This action of "thinking about it then saying something" could easily be done with two huge panels that you have to scroll through, but when you view them together side by side it allows you to "see" the character moving in your head.
So... did I choose page format? No
... I compromised. I ultimately went with a vertical format that favors more panels per visible area. I think this still qualifies as vertical scroll format it just ignores the "single panel per visible area" trend.
tldr; I went with vertical scroll in the end, but ignored the trend of single panel.