Originally Posted by NickB

You forget one thing in your comparison: you get in X hours early but you also have to leave from origin Y hours early., which is not at all the same kind of thing. Having to leave from origin earlier is at least as inconvenient as arriving late at destination. IMO, the approach of the ECJ on this makes perfect sense:

Telling me: "we can get you at destination at the same time as originally planned but you have to leave from origin 10 hours earlier" is just as inconvenient as telling me "you leave as planned but we will get you at destination 10 hours later". I don't quite see why compensation should be cut by 50% in the former situation compared to the latter.