I just ugraded from 58.XXX to 60.0.3255.27. For a number of reasons, like a lot of people, I like to have the tabs below the address bar. I had somehow found a way to do this in 58.XXX but can't remember what it was. I can't find a way to do it 60.0.3255.27.
I know this seems like a minor thing but it seems to me that it would not be overly difficult to give the user the option of locating the tabs above or below the address bar. The loss of features or the ability to customize which users value causes them to eventually change browsers. Like many others, I'm using Opera after having become disenchanted with IE and then with Firefox. Another consideration is that removing features valued by users may cause them to stop updating, exposing them to security vulnerabilities.