I know that everybody's day starts earlier. Whether or not it's more efficient, that's probably something you'd have to ask members.
Again, members who have different roles in the House have a different experience. I think probably for cabinet ministers it's good for them. By noon their responsibility in the House, unless they have legislation that's related to their ministry, is done. They can get on with the business of their ministry.
On the other hand, for the opposition, for some of those members it's the same situation. If they have things to do in the afternoon, their afternoon can be largely free. At the same time, it does require a much earlier start time for things like question period and the committees that each caucus has.