I've never applied it unless such a restriction was listed in that countrie's AIP. Descending, unless assigned a higher speed, I normally followed a similar profile to the US just because it works better with energy management given my usual habits. On climbout though, "let 'er eat".
In the 121 world now most procedures have speed restrictions that take the ambiguity out, but I do remember one time in Europe being given a "high speed climb approved" after checking in with Radar after takeoff and it was glorious.