Simply it may be a bug or a feature. In 1.3 left join returns f.e 2 objects in a single result object. In 2.0 it does too. But in 1.3 i have number 2 when i use count($model), and number 1 in 2.0. I'll find a way to deal with it but just wanted to say that something like that happened - my volt template check this number to "decide" what to do.