I've also switched to Opera a couple of months ago. I'm running Opera touch on android too. I've found Opera on desktop (Linux) to be faster than Firefox and Chrome and the only functionality I'm missing is "to move the tabs to left and right". Even the chromecast works on Opera, which is fantastic. I've been using the Flow functionality ever since I've started using Opera, and I think that is the second reason (well, after it being fast) I'm going to stick with Opera.

Strangely, I've also found that Opera's android browser is by far the fastest, very noticeably.