Absolutely this. I tend to put my browser on a monitor that's been rotated vertically so I have tonnes of vertical screen real estate. I have a bunch of common tabs pinned, and the current design doesn't let me take advantage of this at all.
This was my main issue with the vertical tabs. I keep 6 tabs pinned at all times and I never want to have to scroll for them. Ideally, I never want to scroll for any number of pinned tabs unless my total number of tabs requires scrolling.
My solution locally was to modify userChrome.css, and add the following:
/* Vertical tabs allow all pinned tabs to show. */
#vertical-pinned-tabs-container {
max-height: none !important;
}