For Windows 8.1, we use a constantly developed high performing alternate browser to the well known orange "Fox", Pale Moon x64. The newest arrival (for us) with a different kind of name is SeaMonkey. It has provided a surprisingly smooth experience for us in a familiar browsing way!
Think of "Explorer", one that works safely. In Windows 7 SP 1, we continue to happily browse in Firefox with nary a hiccup.
Though honorable mention goes to Opera, the performance award for a Chromium browser (on our newer system) goes to Slimjet which not only performs well, it's also kept current with frequent updates as it follows in it's Bigger Chrome brother's footsteps with a considerably lighter step!