One thing that stands out to me right away is that it seems like in the vertical scroll formatted one, the panels are still the same size (or roughly the same) as in the page format one, if I'm not mistaken? If you do go that route I would personally recommend taking advantage of the format and size up some of the panels to read more easily. That's not to say that every panel has to be full width or super huge or anything, but the main advantage of vertical scroll is legibility on smart phones, and there all the size increase you can get, the better!
If you're not that interested in scaling the panels up at all, then I don't know that there's much disadvantage just going with the regular pages tbh
at that point it's more about the reading flow I suppose, it's definitely a little faster to read a page when you have access to all of the panels at a glance, vs. spacing them apart.
I absolutely don't claim to be a pro at vertical scroll as I'm only currently working on my first vertical comic atm, but I did a similar exercise to what you did earlier this year and found the ability to scale up some panels, especially ones where I had 2 or 3 in a single row, was useful 
Comic Page:
https://tapas.io/episode/1205248
Vertical:
https://tapas.io/episode/1705405