The feature "generally" shouldn't break legitimate site behavior. It will, however, put extra strain on your system. Google believes there's a 10 to 13 percent memory overhead compared to earlier versions since it'll need to run processes for each site.

The company promises "additional security checks" in the future, including safeguards when an attack has already been compromised. Mobile users will have protections, too, with Chrome 68 for Android will adding an experimental Site Isolation flag. These initiatives don't guarantee that you'll be immune to Spectre and its kind, but they should cut off some of the more obvious avenues for stealing your info.