I've been using UX on Mac and Linux for a few months – love the tabs in the titlebar on Mac – and rarely have problems. A few extensions aren't compatible, and occasionally a build is unstable, so I also have Firefox (stable) and Aurora installed. I just restart into a (more) stable release if there is an issue. They all use the same profile, so settings and tabs are shared. Lazy-loading for tabs make restarting not much of an issue, even with a couple dozen tabs open.