I care more about my demographic, my profession and role in society then I do about the local area I happen to live in right now. Geographic constituencies are a relic of the feudal past. Sure, local issues should be discussed at some point but it's really not a good way to represent the population and the actual range of viewpoints in society.
I would say geography is very relevant for local government and regional govenrment. But maybe for federal government its not as relevant.
How would federal voting work in your system? Are there any actual proposals? How would you form a parliament?