I'm not that happy with native browser speed as well - even though it got a bit better with Sailfish OS 1.1.4.28.

Most of the time I use "Web Pirate" (available from OpenRepos/Warehouse). Works great for me and I like the way it plays videos (even adds cover-actions for video playback). It also offers more traditional tab browsing and you can add shortcuts to website like in Firefox.

Otherwise I also use Firefox Android app (mainly because of sync feauture).