I don't like the way it handles bookmarks but the browsing speed is nice. I tried FF, Chrome, Opera and while they all worked good I still keep coming back to Dolphin. On my laptop I use FF or Chrome (I find Chrome does not play well with a lot of sites).
I used to use Opera all the time and still like it but development stopped (just restarted) on the Linux version so I moved away from it. I did try the Droid version and yes it does work nice.
I like the way Opera handle tabs and bookmarks. I had used Opera a few years ago on PC but have not since. I use IE 11 or Firefox nightly builds for 64 bit. I am new to opera on droid but I do like it a lot.