I was strongly against this measure. This convention is a perfect example of why.
We've all seen the way people win in one member one vote races - Stockwell Day eclipsing Preston Manning with massive church sign ups, Bernard Lord beating Norm Betts with a few kegs at U de M and so on. It is a bad way to choose a leader.
In this sort of race in particular, when it requires a lot of deliberation and people moving to their 2nd, 3rd and even 4th choices by the time the balloting leads up. Some deride deals on the floor but it is more than that.
I have encountered delegates here in Montreal who have said, of all the big four candidates, that they were impressed or disappointed to get to see them up close. These delegates are going to make informed decisions that could never be made under OMOV and the party will have a better leader for it.