Wow! Those are some big homes...
I went to visit the Building a New Home forum. Wow! They have some big homes...beautiful, but big.
While I have nothing against big homes, we don't have a large family (well, not living with us) so a smaller homes suits us much better.
I do like a little extra space, but I think I often end up with alcoves, rather than rooms. The benefit...there is a feeling of a separate space, but everyone is still part of the larger group.
The 'big home' people all seem very nice and very excited about their new homes. I say good for them...but I will not envy them their heating bills :)