I love teaching to large (50+ students) classes - full stop. There is a dynamism that cannot be measured - I love the banter, interactivity, challenge, friendliness, that does not exist in smaller classes. While I am happy to work with small classes - nothing beats standing in front of a group of 50+ students and engaging in learning and teaching. It's what I live for.
If given the opportunity to lecture to 5 students or 50 is presented to me - I will go for 50 every time, regardless of time table.
There is no straight answer to "Larger or Smaller Classes - Which is Best?". But there is a buzz in larger classes that cannot be replicated in smaller classes.