QAbstractItemModel has following signal:
void dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles = QVector<int> ())

QAbstractItemView has corresponding protected virtual method:
void QAbstractItemView::dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles = QVector<int> ()) [virtual protected slot]

If you add QSortFilterProxyModel (or subclass) between model and view, view receives empty roles vector. As a result, all the pros of that parameter added in Qt 5.0 are negated if QSortFilterProxyModel is used.

See example in attachment.