For us, it was very much the same experience with my children. My first child was so easy, so happy, so adaptable to any situation I wondered what the big deal was with having two children a year apart. Same thing happened with our Newfs. 'Bella was so easy, so happy, and so well adaptable to situations. So we brought home Gabe one year and one month later.
Well, second children and second puppies are not necessarily the same in personality as the first child and first puppy.
All that being said, I wouldn't have changed either for the world.
Do not expect that it will all be the same, but in my experience it just makes life even more grand (if that is possible!) I'm ready for my third Newf. (I've had my three children and no longer need/want/or am able for the human variety!)