1. Not supporting any features that trigger a layout recalculation is a pretty major drawback, I'd say. The complaint I hear most about CSS is that it's actually terrible for layouts, and while flex is a step in the right direction it still has a long way to go.
2. Houdini is specifically proposed to address the issue of browsers not implementing specs quickly enough. Now they'll have yet another spec to implement, and it's intended to "just work" in all the browsers, except it'll depend on what version of the spec the various browsers have implemented, taking us right back to square one.
2. Houdini is specifically proposed to address the issue of browsers not implementing specs quickly enough. Now they'll have yet another spec to implement, and it's intended to "just work" in all the browsers, except it'll depend on what version of the spec the various browsers have implemented, taking us right back to square one.