There very different for me. I had a 20G setup for a long time, There were certain things that were cool like nothing could hide. I could always find my fire shrimps, etc. They are a peice of cake with maintenance and any problem is easily corrected because you can do a huge water change in a breeze.
The 450 is awesome though. I can have any fish I want, I can create different areas in the tank (super high flow on one side while medium on another for different types of corals, etc, it's just a lot more flexible! It's almost like sensory overload looking at it though. There is so much to look at. Sure it's more work and time and it's true thinngs like broken frags and stuff never get discovered but in a big tank you can do literally whatever you want and your very limited in a nano.