Earlier quoted context omitted.
> I'd like to know if there are reasons to move to canvas for strictly technical merits. In Google's announcements, they say the reason is performance.
That seems like a moderately weak argument. DOM tables are slow, but if you know what you are doing the DOM is otherwise an insanely fast interface. You can get sub-nanosecond response speed from DOM calls in Firefox (faster than a billion operations per second). It would be interesting to see the performance differences in numbers. The performance impact of a canvas based approach can be approximated from measuring…
And yes, tables are slow. "If you know what you're doing" routinely becomes "let's reinvent virtual lists on an interface that doesn't have a single API to make this pleasant or performant in any conceivable way".