Well, I've finally given it a try. That's the official version, which I'm happy enough with for now (I was happy with Mozilla's official builds of Firefox for a long time, this isn't really much different), though I've noticed some things that I immediately don't like. Also, yes, 7/b/ is my homepage (the screenshot chosen appears to be as worksafe as /b/ can possible be). 4/b/ is dead to me.
1) The tab bar. This is the biggest issue, and I spotted it as soon as the 'tabs on top' thing was suggested. I have an auto-hiding panel at the top of my screen, in the centre, taking up about 80% of the screen width. If I have tabs right at the top of the screen while the browser is maximized (and it is maximized, all the time), then I keep floating the panel by mistake. I've partially solved this by re-enabling the title bar (I'll probably leave that there) but a more permanent solution would be to place the tab bar underneath the location bar, the location bar being rarely used enough these days that it wouldn't be nearly as annoying. Unfortunately, I see no way of doing this right now.
2) You can see two buttons to the right of the location bar, which I will call Page Control and Chrome Control. There's also a button to the right of the bookmarks bar, which I will call Other Bookmarks. To my mind, these are all in the wrong place. Putting them on the right means the menus that they spawn sub-menus to the left of the original, unlike every other menu on my system. I would effectively 'flip' these, placing all of these buttons on the right. The location bar line would thus be Chrome Control, Page Control, Back, Forward, Refresh (and Home if present), then the location bar itself. The bookmarks bar line would start with Other Bookmarks, then have the bookmarks toolbar. Again, I see no way of doing this right now.
3) I can get rid of the 'Classic Theme' (which I considered to be ugly and hard to use) in favour of my default GTK+ theme, but it seems the scroll bar and page widgets use Chrome's theme no matter what. This has some practical advantages for the page widgets, but I don't see why the scroll bar must follow, and they both look ugly next to my GTK+ theme anyway. Also, the scroll bar doesn't do smooth scrolling and has no scroll buttons (Google may think these are a bad idea, but I'd like a say in the matter too thank you very much).
Aside from these three issues (which may be solvable in ways that I haven't found yet), the browser does seem promising though. It'd be nice to see Chromium or some other derivative in Debian someday.